System for producing urea by coupling blast furnace gas with coke oven gas
The system of urea produced by blast furnace gas coupled coke oven gas is used to produce chemical urea using the useful components in blast furnace gas and coke oven gas, which solves the problem of high carbon emissions during blast furnace iron smelting, and achieves a low-cost and efficient deep carbon reduction effect.
Patent Information
- Application Number
- CN202422328689.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-24
- Publication Date
- 2025-07-08
- Estimated Expiration
- 2034-09-24
AI Technical Summary
In the prior art, carbon emissions are high during blast furnace iron smelting, making it difficult to effectively utilize useful components in blast furnace gas and coke oven gas, and the carbon reduction effect of traditional methods is limited.
The system of urea produced by blast furnace gas coupled to coke oven gas is used to produce chemical products urea through blast furnace gas, and hydrogen-rich injection and deep carbon reduction in blast furnace gas are used to purify and convert.
The effective utilization of blast furnace gas and coke oven gas is achieved, cost and energy consumption is reduced, carbon reduction effect is improved, carbon emissions is reduced, and blast furnace operation is stabilized.
Smart Images
Figure CN223069498U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of blast furnace ironmaking, and specifically relates to a system for producing urea by coupling blast furnace gas and coke oven gas. Background Art
[0002] In the long process of blast furnace ironmaking, 75% of the energy directly or indirectly comes from coal. The carbon metallurgy process mainly based on fossil energy uses C or CO as a reducing agent, and the final products are CO or a mixture of CO and CO2. If part or all of the hydrogen-containing gas is used to replace the blast furnace reducing agent, carbon reduction can be achieved but the effect is limited. The by-products in the iron and steel industry, blast furnace gas and coke oven gas, are good chemical raw materials. On the one hand, by using CO, CO2, H2 and N2 in blast furnace gas, and CH4 and H2 in coke oven gas, after purification and conversion treatment, hydrogen-rich gas injection can be realized; useful components can also be chemically synthesized to fix carbon in chemical products for deep carbon reduction. Summary of the Utility Model
[0003] In order to recycle blast furnace gas and coke oven gas, the utility model provides a system for producing urea by coupling blast furnace gas and coke oven gas. The system for producing urea by coupling blast furnace gas and coke oven gas makes full use of the useful components in blast furnace gas, couples coke oven gas to realize hydrogen-rich injection in the blast furnace, and produces the chemical product urea, which has the advantages of low cost, low energy consumption, good carbon reduction effect, etc., and is an effective direction and way for deep carbon reduction.
[0004] The technical solution adopted by the utility model to solve its technical problems is:
[0005] A system for producing urea by coupling blast furnace gas and 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 of the blast furnace gas treatment pipeline to the outlet of the blast furnace gas treatment pipeline, the blast furnace gas treatment pipeline successively includes a CO conversion device, a CO2 removal device, a purification device, a synthetic ammonia device and a synthetic urea device. The inlet of the blast furnace gas treatment pipeline is connected to the outlet of the blast furnace, and the CO2 outlet of the CO2 removal device is connected to the CO2 inlet of the synthetic urea device through a CO2 pipeline; along the direction from the inlet of the coke oven gas treatment pipeline to the outlet of the coke oven gas treatment pipeline, the coke oven gas treatment pipeline successively includes a refining device, a pressure swing adsorption hydrogen production device and a heating device. The inlet of the coke oven gas treatment pipeline is connected to the coke oven, the outlet of the coke oven gas treatment pipeline is connected to the blast furnace, and the H2 outlet of the pressure swing adsorption hydrogen production device is connected to the H2 inlet of the synthetic ammonia device through an H2 pipeline.
[0006] Along the direction from the inlet of the blast furnace gas treatment pipeline to the outlet of the blast furnace gas treatment pipeline, the blast furnace gas treatment pipeline further comprises a dust removal device, a power generation device and a desulfurization device which are connected in sequence. The dust removal device, the power generation device and the desulfurization device are located between the blast furnace and the CO conversion device.
[0007] The dust removal device can remove dust from the blast furnace gas. The power generation device can generate electricity by using the pressure energy and heat energy of the blast furnace gas. The desulfurization device can desulfurize the blast furnace gas.
[0008] The blast furnace gas treatment pipeline further comprises a pressurizing device which is located between the desulfurization device and the CO conversion device.
[0009] The CO conversion device can make CO and water vapor in the blast furnace gas react to generate CO2 and H2. The CO2 removal device can separate the CO2 generated in the CO conversion device and discharge it from the CO2 outlet of the CO2 removal device. The purification device can purify the H2 generated in the CO conversion device and the N2 in the blast furnace gas.
[0010] The ammonia synthesis device can make H2 generated in the CO conversion device, H2 separated by the pressure swing adsorption hydrogen production device and N2 in the blast furnace gas react to generate NH3. The urea synthesis device can make NH3 generated by the ammonia synthesis device and CO2 discharged from the CO2 removal device react to generate urea.
[0011] The refining device can adsorb and purify tar, benzene, naphthalene, organic sulfur and inorganic sulfur in the coke oven gas. The refining device comprises a filtering unit, and the filtering unit is a molecular sieve.
[0012] The heating device comprises an inlet for the medium to be heated and an outlet for the medium to be heated. The heating device is an electric heating device or a fuel heating device.
[0013] The blast furnace comprises a hearth tuyere and a lower part tuyere of the furnace body. The outlet of the coke oven gas treatment pipeline is connected to the hearth tuyere and the lower part tuyere of the furnace body.
[0014] The outlet of the desulfurization device is connected with an external supply pipeline for blast furnace gas. The outlet of the urea synthesis device is connected with an external supply pipeline for urea. The H2 transmission pipeline is connected with a green hydrogen supply pipeline.
[0015] The beneficial effects of the utility model are as follows:
[0016] 1. By adopting blast furnace gas purification and conversion treatment, using CO2, N2, H2 therein and hydrogen in the coke oven gas to synthesize urea; the methane-rich tail gas after hydrogen extraction from the coke oven gas is heated and sent to the blast furnace for injection.
[0017] 2. Make full use of N2 in the blast furnace gas, convert it into high-value chemical products, and the cost is low.
[0018] 3. The carbon in blast furnace gas is recycled by injecting hydrogen-rich gas into the blast furnace, which is beneficial to carbon reduction in the blast furnace.
[0019] 4. The blast furnace adopts oxygen-enriched blowing. On the one hand, it reduces the scale of oxygen production equipment. On the other hand, it has little impact on the transformation and operation methods of the blast furnace, which is beneficial to the stability of the blast furnace system.
[0020] 5. The carbon in blast furnace gas is synthesized into urea, which not only utilizes the components in the gas but also is beneficial to the deep decarbonization of the blast furnace, with good carbon reduction effect, providing a feasible path for large-scale carbon reduction in the blast furnace. Description of the Drawings
[0021] The schematic diagrams of the drawings forming a part of this application are used to provide a further understanding of the present utility model. The schematic embodiments and descriptions thereof of the present utility model are used to explain the present utility model and do not constitute an improper limitation to the present utility model.
[0022] Figure 1 It is a schematic diagram of the system for producing urea by coupling blast furnace gas and coke oven gas of the present utility model.
[0023] Figure 2 It is a schematic diagram of the heating device.
[0024] Description of the Reference Numerals in the Drawings
[0025] 1. Blast furnace; 2. Dust removal device; 3. Power generation device; 4. Desulfurization device; 5. Pressurization device; 6. CO conversion device; 7. CO2 removal device; 8. Purification device; 9. Ammonia synthesis device; 10. Urea synthesis device; 11. Refining device; 12. Pressure swing adsorption hydrogen production device; 13. Heating device; 14. Blast furnace gas treatment pipeline; 15. Coke oven gas treatment pipeline;
[0026] 101. Hearth tuyere; 102. Lower part of the furnace body tuyere;
[0027] 401. Blast furnace gas external supply pipeline;
[0028] 701. CO2 transportation pipeline;
[0029] 1001. Urea external supply pipeline;
[0030] 1201. H2 transportation pipeline; 1202. Green hydrogen supply pipeline;
[0031] 1301. Inlet of the medium to be heated; 1302. Outlet of the medium to be heated. Detailed Embodiments
[0032] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The present utility model will be described in detail below with reference to the drawings and in combination with the embodiments.
[0033] For the convenience of understanding and description, the following description of the present utility model adopts absolute position relationships. Without special instructions, the directional term "upper" herein refers to Figure 1 the upper side direction in Figure 1 it, the directional term "lower" refers to Figure 1 the lower side direction in Figure 1 it, the directional term "left" refers to Figure 1 the left side direction in Figure 1 it, the directional term "right" refers to
[0034] the right side direction in Figure 1 it, the directional term "front" refers to the direction perpendicular to
[0035] the paper surface of
[0036] and pointing to the inner side of the paper surface, and the directional term "rear" refers to the direction perpendicular to Figure 1 the paper surface of Figure 1 it and pointing to the outer side of the paper surface. The present utility model describes from the observation perspective of the reader or user, but the above directional terms should not be understood or interpreted as limiting the protection scope of the present utility model. Regarding the dimensions and angles of the components therein, those skilled in the art can specifically determine them according to actual needs or through limited experiments.
[0034] As Figure 1 shown, a system for producing urea by coupling blast furnace gas and coke oven gas according to an embodiment of the present utility model 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 of the blast furnace gas treatment pipeline 14 to the outlet of the blast furnace gas treatment pipeline 14, the blast furnace gas treatment pipeline 14 successively includes a CO conversion device 6, a CO2 removal device 7, a purification device 8, a synthetic ammonia device 9, and a synthetic urea device 10. The inlet of the blast furnace gas treatment pipeline 14 is connected to the outlet of the blast furnace 1, and the CO2 outlet of the CO2 removal device 7 is connected to the CO2 inlet of the synthetic urea device 10 through a CO2 delivery pipeline 701; along the direction from the inlet of the coke oven gas treatment pipeline 15 to the outlet of the coke oven gas treatment pipeline 15, the coke oven gas treatment pipeline 15 successively includes a refining device 11, a pressure swing adsorption hydrogen production device 12, and a heating device 13. The inlet of the coke oven gas treatment pipeline 15 is connected to a coke oven, the outlet of the coke oven gas treatment pipeline 15 is connected to the blast furnace 1, and 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 an H2 delivery pipeline 1201.
[0035] The blast furnace gas contains CO, CO2, H2O, H2, and N2, and the coke oven gas contains CH4 and H2. The blast furnace gas generated by the blast furnace 1 enters the blast furnace gas treatment pipeline 14, and the coke oven gas generated by the coke oven enters the coke oven gas treatment pipeline 15. The system and method for producing urea by coupling blast furnace gas and coke oven gas make full use of the useful components in the blast furnace gas, couple the coke oven gas to achieve hydrogen-rich injection in the blast furnace, and produce the chemical product urea, having the advantages of low cost, low energy consumption, good carbon reduction effect, etc., and being an effective direction and approach for deep carbon reduction.
[0036] As Figure 1As shown, 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 blast furnace gas treatment pipeline 14 further includes a dust removal device 2, a power generation device 3, and a desulfurization device 4 that are 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.
[0037] The blast furnace gas treatment pipeline 14 further includes a pressurizing device 5, and the pressurizing device 5 is located between the desulfurization device 4 and the CO conversion device 6. The pressurizing device 5 can pressurize the blast furnace gas to 0.6 Mpa - 2.0 Mpa. The outlet of the desulfurization device 4 can be connected with an external supply pipeline.
[0038] The desulfurized blast furnace gas is pressurized by the pressurizing device 5, and after the pressure is increased, it enters the CO conversion device 6, where the CO in the blast furnace gas is converted into H2 and CO2, and then enters the CO2 removal device 7. The CO2 removal device 7 separates the CO2 in the blast furnace gas conversion gas and sends it to the synthetic urea device 10 as a raw material.
[0039] The dust removal device 2, the power generation device 3, the desulfurization device 4, and the pressurizing device 5 can all adopt existing technology products. For example, the power generation device 3 can include a steam turbine, and the desulfurization device 4 can adopt the method of molecular sieve adsorption to remove the organic sulfur and inorganic sulfur therein. The desulfurized blast furnace gas can be externally supplied and used to synthesize chemical products.
[0040] The CO conversion device 6 can enable the reaction of 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 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.
[0041] The synthetic ammonia device 9 can enable the reaction of 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 generate NH3. The synthetic urea device 10 can react the NH3 generated by the synthetic ammonia device 9 with the CO2 discharged from the CO2 removal device 7 to generate urea.
[0042] As Figure 1As shown, the CO shift unit 6, the CO2 removal unit 7, the purification unit 8, the synthetic ammonia unit 9, and the synthetic urea unit 10 can all adopt existing technology products. The gas after decarbonization is rich in H2 and N2, and then enters the purification unit 8 to remove the impurities therein, and is further purified and sent to the synthetic ammonia unit 9. The synthetic ammonia reacts with CO2 in the synthetic urea unit 10 to prepare urea, fixing the CO2 and N2 in the blast furnace gas in the product, greatly reducing CO2 emissions and achieving deep decarbonization.
[0043] The refining unit 11 can adsorb and purify tar, benzene, naphthalene, organic sulfur, and inorganic sulfur in the coke oven gas. The refining unit 11 contains a filtration unit, and the filtration unit can be a molecular sieve, and the material of the filtration unit can also be a microcrystalline material. The purified coke oven gas enters the pressure swing adsorption hydrogen production unit 12.
[0044] The function of the pressure swing adsorption hydrogen production unit 12 is to extract H2 from the coke oven gas, and the pressure swing adsorption hydrogen production unit 12 can separate and discharge the H2 in the coke oven gas. The rich methane tail gas after pressure swing adsorption hydrogen production in the pressure swing adsorption hydrogen production unit 12 enters the heating unit 13; the rich methane gas is heated in the heating unit and then sent to the blast furnace 1. The H2 pipeline 1201 can be connected with a green hydrogen supply pipeline 1202.
[0045] As Figure 2 shown, the refining unit 11, the pressure swing adsorption hydrogen production unit 12, and the heating unit 13 can all adopt existing technology products. The heating unit 13 contains a heated medium inlet 1301 and a heated medium outlet 1302, and the heating unit 13 is an electric heating unit or a fuel heating unit, that is, the heat source of the heating unit 13 can be electricity or fuel (such as fuel oil or coal).
[0046] The pressure swing adsorption hydrogen production unit 12 contains an inlet, a filtration outlet, and an H2 outlet. The inlet of the pressure swing adsorption hydrogen production unit 12 is communicated with the outlet of the refining unit 11, the filtration outlet of the pressure swing adsorption hydrogen production unit 12 is communicated with the heated medium inlet 1301 of the heating unit 13, and the heated medium outlet 1302 of the heating unit 13 is communicated with the hearth tuyere 101 and the lower part of the furnace body tuyere 102 of the following blast furnace 1.
[0047] The blast furnace 1 contains a hearth tuyere 101 and a lower part of the furnace body tuyere 102, and the outlet of the coke oven gas treatment pipeline 15 is connected with the hearth tuyere 101 and the lower part of the furnace body tuyere 102. The pressure of the outlet gas (rich methane tail gas) of the heating unit 13 is 0.2 MPa - 0.6 MPa (preferably 0.2 MPa - 0.4 MPa), the temperature is 800 °C - 1100 °C, and it is blown into the hearth tuyere 101 and the lower part of the furnace body tuyere 102, and the injection volume is 50 m 3 / tFe - 150 m 3 / tFe, and the injection method can be flexibly adjusted according to the production situation.
[0048] The outlet of the desulfurization device 4 is connected to the blast furnace gas external supply pipeline 401, the outlet of the synthetic urea device 10 is connected to the urea external supply pipeline 1001, and the H2 transmission pipeline 1201 is connected to the green hydrogen supply pipeline 1202.
[0049] The connection relationships in the system for producing urea by coupling blast furnace gas and coke oven gas are introduced below. The top gas outlet of the blast furnace 1 is connected to the dust removal device 2, the outlet of the dust removal device 2 is connected to the inlet of the power generation device 3, and the outlet of the power generation device 3 is connected to the desulfurization device 4. The gas at the outlet of the desulfurization device 4 can be supplied externally or connected to the pressurization device 5; the outlet of the pressurization device 5 is connected to the CO conversion device 6, the outlet of the CO conversion device 6 is connected to the CO2 removal device 7, and the CO2 removal device 7 is respectively connected to the synthetic urea device 10 and the purification device 8; the inlet of the purification device 8 is connected to the CO2 removal device 7, the outlet of the purification device 8 is connected to the synthetic ammonia device 9, and the inlet of the synthetic ammonia device 9 is connected to the outlet of the purification device 8, the green hydrogen supply pipeline, and the hydrogen extraction outlet of the pressure swing adsorption hydrogen production device 12; the outlet of the synthetic ammonia device 9 is connected to the synthetic urea device 10, and the synthetic urea product is supplied externally. The coke oven gas inlet is connected to the refining device 11 (which can also be called the refining device), the outlet of the refining device 11 is connected to the pressure swing adsorption hydrogen production device 12, the hydrogen extraction outlet of the pressure swing adsorption hydrogen production device 12 is connected to the inlet of the synthetic ammonia device 9, and the methane-rich tail gas pipeline after hydrogen extraction is connected to the inlet of the heating device 13, and the outlet of the heating device 13 is connected to the tuyere of the blast furnace 1.
[0050] A method for utilizing the coupling of blast furnace gas and coke oven gas is introduced below. The method for utilizing the coupling of blast furnace gas and coke oven gas adopts the above-mentioned system for producing urea by coupling blast furnace gas and coke oven gas, and the method for utilizing the coupling of blast furnace gas and coke oven gas includes the following steps:
[0051] As Figure 1 shown, the blast furnace gas enters the blast furnace gas treatment pipeline 14. The CO conversion device 6 causes the CO and water vapor in the blast furnace gas to react 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 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 synthetic ammonia 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. The synthetic urea device 10 causes the NH3 generated by the synthetic ammonia device 9 and the CO2 discharged from the CO2 removal device 7 to react to generate urea;
[0052] The coke oven gas enters the coke oven gas treatment pipeline 15, the refining device 11 adsorbs and purifies the coke oven gas, the pressure swing adsorption hydrogen production device 12 separates H2 from the coke oven gas and discharges the methane-rich tail gas, the heating device 13 heats the methane-rich tail gas, and the heated methane-rich tail gas enters the blast furnace 1 for ironmaking.
[0053] The utilization method of coupling the blast furnace gas and the coke oven gas is introduced in detail below.
[0054] The blast furnace gas discharged from the blast furnace 1 enters the inlet of the blast furnace gas treatment pipeline 14. The blast furnace gas flows through the dust removal device 2, the power generation device 3, the desulfurization device 4, the pressurization device 5, the CO conversion device 6, the CO2 removal device 7, the purification device 8, the synthetic ammonia device 9 and the synthetic urea device 10 in sequence. Finally, the produced urea can be supplied externally.
[0055] The dust removal device 2 removes dust from the blast furnace gas, the power generation device 3 generates electricity using the pressure energy and heat energy of the blast furnace gas, and the desulfurization device 4 desulfurizes the blast furnace gas. The desulfurization device 4 can be a molecular sieve dry desulfurization device, and the total sulfur is removed to less than 1mg / Nm 3 . The pressurization device 5 pressurizes the blast furnace gas to 0.6 Mpa - 2.0 Mpa. The pressurized blast furnace gas enters the CO conversion device 6, and the CO in the blast furnace gas reacts with steam to generate CO2 and H2.
[0056] The CO conversion device 6 makes the CO in the blast furnace gas react with steam (H2O) 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 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.
[0057] The CO2 removal device 7 can adopt a wet removal device. Preferably, the alcohol amine method is used to remove CO2 from the syngas. After removal, the main components in the syngas are H2 and N2. The syngas leaving the CO2 removal device 7 is further purified for H2 and N2 by the purification device 8, and the purified syngas enters the synthetic ammonia device 9.
[0058] The synthetic ammonia device 9 makes 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 react to generate NH3. The synthetic urea device 10 makes the NH3 generated by the synthetic ammonia device 9 react with the CO2 discharged from the CO2 removal device 7 to generate urea.
[0059] Part of the hydrogen required by the ammonia synthesis unit 9 comes from the conversion of the original blast furnace gas, and part comes from the hydrogen extraction from the coke oven gas; green hydrogen can be supplemented as needed. The produced ammonia is transported to the urea synthesis unit 10 to synthesize urea products with CO2, fixing the C in the blast furnace gas in the products and achieving deep decarbonization. The inert gases N2 and CO2 in the blast furnace gas are fully utilized, and no additional nitrogen production device is required.
[0060] The coke oven gas discharged from the coke oven enters the inlet of the coke oven gas treatment pipeline 15. The coke oven gas flows through the refining device 11, the pressure swing adsorption hydrogen production device 12, and the heating device 13 in sequence. The methane-rich tail gas after the coke oven gas discharged from the coke oven is treated by the coke oven gas treatment pipeline 15 enters the blast furnace 1.
[0061] The refining device 11 adsorbs and purifies the tar, benzene, naphthalene, organic sulfur, and inorganic sulfur in the coke oven gas. The pressure swing adsorption hydrogen production device 12 separates and discharges the H2 in the coke oven gas, and the discharged H2 is sent to the ammonia synthesis unit 9. The CH4 in the coke oven gas is heated in the heating device 13 and then sent into the blast furnace 1 for ironmaking. Oxygen enrichment and pulverized coal can also be added into the blast furnace 1 through the tuyeres 101 of the hearth to ensure that the theoretical combustion temperature in the raceway is between 1900°C and 2100°C. The oxygen enrichment is adjusted according to production. Preferably, in the mixture of oxygen enrichment and pulverized coal, the mass fraction of oxygen enrichment is 21%-50%.
[0062] The actual usage of the utilization method of coupling blast furnace gas and coke oven gas is introduced in detail below.
[0063] As Figure 1 shown, the preliminarily purified coke oven gas is 70000 Nm 3 / h, among which, H2 is 58%, CO is 6%, CO2 is 2%, N2 is 5%, CH4 is 26%, and others are 3%. It enters the refining device 11, is adsorbed and purified by using molecular sieves, removing impurities such as inorganic sulfur, organic sulfur, benzene, naphthalene, and tar, and is sent to the pressure swing adsorption hydrogen production device 12 to extract H2, which is sent to the ammonia synthesis unit 9. The pressure swing adsorption tail gas is rich in CH4 and is sent to the heating device 13. It is heated therein to obtain high-temperature reducing gas with a temperature of 1000°C and is hot-sent to the tuyeres of the hearth of the blast furnace 1. Pulverized coal and oxygen enrichment are simultaneously injected at the tuyeres of the hearth, and the oxygen enrichment concentration is 35%, and the concentration can be adjusted according to production. The theoretical combustion temperature in the tuyere area is 2000°C. Reduction reactions occur in the blast furnace 1 to generate molten iron and slag. The gas undergoes reactions in the blast furnace to generate CO2 and H2O and is discharged from the top of the furnace.
[0064] The blast furnace gas discharged from the top of the blast furnace 1 passes through the dust removal device 2 and the power generation device 3 in sequence, with a dust concentration less than 10 mg / m 3 , and is sent to the desulfurization device 4. The blast furnace gas coming out of the desulfurization device, among which 200000 Nm 3The gas at / h enters the pressurizing device 5, is pressurized to 1.0 Mpa, and then sent to the CO conversion device 6. CO and water vapor in the blast furnace gas react under the action of a catalyst to produce H2 and CO2, which is called syngas. The syngas is sent to the CO2 removal device 7 to remove and separate CO2 from the syngas. The separated CO2 is sent to the synthetic urea device 10. The decarbonized syngas is rich in H2 and N2, and then sent to the purification device 8 to further purify N2 and H2. The purified syngas is sent to the synthetic ammonia device 9 to produce ammonia. The synthesized ammonia is sent to the synthetic urea device 10, where it reacts with CO2 to produce urea, and the urea is sold as a chemical product.
[0065] The utility model adopts the purification and conversion treatment of blast furnace gas, and uses the CO2, N2, and H2 therein and the hydrogen in the coke oven gas to synthesize urea; the methane-rich tail gas after hydrogen extraction from the coke oven gas is heated and then sent to the blast furnace to realize the injection of hydrogen-rich gas into the blast furnace. It solves the problem of the extraction and utilization of N2 in the blast furnace gas; it solves the problem of hydrogen injection and carbon reduction in the blast furnace itself; the synthesized urea fixes carbon and solves the problem of the deep treatment of carbon in the blast furnace gas. It has the advantages of low cost and deep carbon reduction.
[0066] As described above, only the specific embodiments of the present utility model are given, and the scope of the implementation of the utility model cannot be limited by them. Therefore, the replacement of equivalent components or the equivalent changes and modifications made according to the protection scope of the present utility model should still fall within the scope covered by the present utility model. In addition, the technical features in the present utility model can be freely combined with each other between technical features, between technical features and technical solutions, and between technical solutions.
Claims
1. A system for producing urea by coupling blast furnace gas and coke oven gas, characterized in that, The system for producing urea by coupling blast furnace gas and coke oven gas 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 of the blast furnace gas treatment pipeline (14) to the outlet of the blast furnace gas treatment pipeline (14), the blast furnace gas treatment pipeline (14) successively includes 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). The inlet of the blast furnace gas treatment pipeline (14) is connected to the outlet of the blast furnace (1), and the CO2 outlet of the CO2 removal device (7) is connected to the CO2 inlet of the urea synthesis device (10) through a CO2 delivery pipeline (701); Along the direction from the inlet of the coke oven gas treatment pipeline (15) to the outlet of the coke oven gas treatment pipeline (15), the coke oven gas treatment pipeline (15) successively includes a refining device (11), a pressure swing adsorption hydrogen production device (12), and a heating device (13). The inlet of the coke oven gas treatment pipeline (15) is connected to the coke oven, the outlet of the coke oven gas treatment pipeline (15) is connected to the blast furnace (1), and the H2 outlet of the pressure swing adsorption hydrogen production device (12) is connected to the H2 inlet of the ammonia synthesis device (9) through an H2 delivery pipeline (1201).
2. The system for producing urea by coupling blast furnace gas and coke oven gas according to claim 1, wherein 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 blast furnace gas treatment pipeline (14) also successively includes a dust removal device (2), a power generation device (3), and a desulfurization device (4). 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).
3. The system for producing urea by coupling blast furnace gas and coke oven gas according to claim 2, wherein 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.
4. The system for producing urea by coupling blast furnace gas and coke oven gas according to claim 2, wherein, The blast furnace gas treatment pipeline (14) also includes a pressurization device (5), and the pressurization device (5) is located between the desulfurization device (4) and the CO conversion device (6).
5. The system for producing urea by coupling blast furnace gas and coke oven gas according to claim 1, characterized in that, The CO conversion device (6) can react CO in the blast furnace gas with steam 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 CO2 outlet of the CO2 removal device (7). The purification device (8) can purify the H2 generated in the CO conversion device (6) and N2 in the blast furnace gas.
6. The system for producing urea by coupling blast furnace gas and coke oven gas according to claim 5, wherein, 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. The urea synthesis device (10) can react NH3 generated by the ammonia synthesis device (9) with CO2 discharged from the CO2 removal device (7) to generate urea.
7. The system for producing urea by coupling blast furnace gas and coke oven gas 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) includes a filtering unit, and the filtering unit is a molecular sieve.
8. The system for producing urea by coupling blast furnace gas and coke oven gas according to claim 1, characterized in that, The heating device (13) includes an inlet (1301) for the medium to be heated and an outlet (1302) for the medium to be heated. The heating device (13) is an electric heating device or a fuel heating device.
9. The system for producing urea by coupling blast furnace gas and coke oven gas according to claim 1, wherein, The blast furnace (1) includes tuyeres (101) in the hearth and tuyeres (102) in the lower part of the furnace shaft. The outlet of the coke oven gas treatment pipeline (15) is connected to the tuyeres (101) in the hearth and the tuyeres (102) in the lower part of the furnace shaft.
10. The system for producing urea by coupling blast furnace gas and coke oven gas according to claim 2, wherein, The outlet of the desulfurization device (4) is connected to an external supply pipeline (401) for blast furnace gas. The outlet of the synthetic urea device (10) is connected to an external supply pipeline (1001) for urea. The H2 transmission pipeline (1201) is connected to a green hydrogen supply pipeline (1202).