Method for decarburizing large-scale coal gas device of hydrogen-rich carbon circulating oxygen blast furnace

Abstract

The invention belongs to the technical field of a process for removing CO2 from metallurgical gas, and particularly discloses a method for decarburizing a large-scale gas device of a hydrogen-rich carbon circulating oxygen blast furnace, which comprises the following steps of: performing dust removal on furnace top gas for three times, feeding the furnace top gas into a compressor for pressurizing, and spraying soft water to cool the compressor while pressurizing, supercharged furnace top gas and liquid spraying soft water are discharged from a compressor together and enter a compressor gas-liquid separator, a first emergency circulating valve and a second emergency circulating valve are used for dealing with the situation when a decarburization system breaks down, the furnace top gas enters an absorption tower, purified gas in the absorption tower is heated through a gas heating furnace and then sprayed into a hydrogen-rich carbon circulating oxygen blast furnace, and the hydrogen-rich carbon circulating oxygen blast furnace is used for decarburization. The amine solution rich solution absorbing CO2 enters a flash tank for flash evaporation, the amine solution rich solution subjected to flash evaporation enters a regeneration tower to generate an amine solution barren solution, the amine solution rich solution is heated by a reboiler or slag flushing water in the process and then returns to the regeneration tower for regeneration, one path of regenerated semi-barren solution is filtered and then returns to the regeneration tower, and the other path of regenerated semi-barren solution enters an absorption tower for recycling.

Description

Technical Field

[0001] The invention relates to the technical field of CO2 removal from metallurgical gas, and in particular to a method for decarbonizing a large-scale gasification device of a hydrogen-rich carbon circulating oxygen blast furnace. Background Art

[0002] The Hydrogen-Enriched Carbon Recirculating Oxygen Blast Furnace (HyCROF) process is a smelting process that uses oxygen blast instead of traditional heated air blast. In order to compensate for the thermodynamic conditions required for the physical and chemical reactions in the blast furnace caused by full oxygen blast, reduction of N2 and sharp reduction in the amount of gas in the furnace, it is necessary to remove CO2 from the top gas to form a reducing gas medium with a higher concentration of reducing components (CO and H2) and spray it into the blast furnace.

[0003] The hydrogen-rich carbon cycle oxygen blast furnace gas contains 25%-35% of CO2 acidic gas. Removing CO2 from the gas can improve its gas reducibility and gas calorific value. At present, the decarbonization method of the hydrogen-rich carbon cycle oxygen blast furnace in the blast furnace converter process in the metallurgical industry is 400m 3 The coal gas decarburization method for blast furnaces of 400m2 and the coal gas decarburization method for Ouye furnace are the first industrial experimental verifications of blast furnace decarburization systems. 3 The process production characteristics of the hydrogen-rich carbon circulating oxygen blast furnace can also adapt to 400m 3 The requirements for carbon reduction and coke ratio reduction in the production of hydrogen-rich carbon circulating oxygen blast furnaces.

[0004] However, this method has the disadvantages of high energy consumption, low efficiency and high cost. 3 The gas generation capacity of the hydrogen-rich carbon cycle oxygen blast furnace is 70,000-100,000 Nm 3 / h, the amount of occurrence is relatively small, which means that if it is to be promoted in large and medium-sized blast furnaces, it will need to process 200,000-450,000 Nm 3 / h of decarbonized coal gas. At present, the blast furnaces in my country's metallurgical industry adopt the principle of large-scale development. If this hydrogen-rich carbon circulating oxygen blast furnace (HyCROF) process technology is to be promoted, especially for the promotion of large and medium-sized blast furnace gas decarbonization process, the gas generation will increase significantly, and it will not be able to meet the carbon reduction requirements of the key core technology of the hydrogen-rich carbon circulating oxygen blast furnace (HyCROF) process, which is to remove CO2 from the top gas and then heat it and inject it into the blast furnace. In order to reduce the carbon content of the first 400m 3 The promotion of hydrogen-rich carbon cycle oxygen blast furnace decarbonization technology to large blast furnaces can reduce carbon emissions, reduce solid fuel consumption, reduce energy consumption, and improve efficiency. 3 The process of the decarburization system of the hydrogen-rich carbon circulating oxygen blast furnace is optimized and improved, and the decarburization methods and equipment are improved and innovated. Summary of the invention

[0005] The purpose of the present invention is to provide a method for decarbonizing a large-scale gasification device of a hydrogen-rich carbon circulating oxygen blast furnace, so as to solve the problems that the gas decarbonization method supporting the hydrogen-rich carbon circulating oxygen blast furnace and the Ouye furnace gas decarbonization method are not suitable for large and medium-sized blast furnace gas CO2 removal processes, and have high energy consumption and low efficiency.

[0006] To achieve the above object, the basic scheme provided by the present invention is: a method for decarbonization of a large-scale gasification device of a hydrogen-rich carbon circulating oxygen blast furnace, comprising the following steps:

[0007] S1: The top gas of the hydrogen-rich carbon circulating oxygen blast furnace is divided into two routes. One route passes through three groups of dust removal processes to remove dust and cool the top gas, reducing the temperature of the top gas from 120-300℃ to ≤40℃. The top gas after dust removal and cooling enters the compressor, and the other route passes through the four-valve group and enters the flash gas pipeline;

[0008] S2: The compressor pressurizes the furnace top gas, and the soft water in the soft water cooler cools the compressor. The compressed gas and the soft water are discharged from the compressor together, and the emergency circulation mode is determined based on the operation of the decarbonization system:

[0009] When the decarbonization system is operating normally, close the emergency circulation valve 1 and the emergency circulation valve 2, and the compressed gas and the spray soft water enter the compressor gas-liquid separator for gas-liquid separation. The separated furnace top gas is discharged from the top of the compressor gas-liquid separator, and the liquid is discharged from the bottom of the compressor gas-liquid separator;

[0010] When the decarbonization system fails, open the emergency circulation valve 1 or emergency circulation valve 2 to start the equipment small circulation or equipment large circulation;

[0011] S3: The liquid discharged from the compressor gas-liquid separator enters the liquid spray soft water heat exchanger, and the top gas discharged from the compressor gas-liquid separator enters the lower part of the absorption tower and is mixed with the amine lean liquid in the absorption tower. The amine lean liquid absorbs CO2 in the top gas to form amine rich liquid. The top gas absorbs CO2 to form purified gas. The amine rich liquid is discharged from the bottom of the absorption tower, and the purified gas is discharged from the top of the absorption tower.

[0012] S4: The purified gas discharged from the top of the absorption tower is divided into two routes. One route first enters the gas heater to heat the temperature from 40-50℃ to 80-100℃, and then enters the expander to reduce pressure after heating. The purified gas after decompression enters the purified gas separation tank. The other route passes through the three-valve group to reduce the purified gas pressure from 1300-1600Kpa to 350-500Kpa, then enters the purified gas separation tank and then enters the gas heating furnace. The amine liquid rich liquid discharged from the bottom of the absorption tower enters the flash tank for flash evaporation. The flash steam after flash evaporation is discharged from the top of the flash tank and enters the gas network together with the furnace top gas after decompression by the four-valve group. The amine liquid rich liquid after flash evaporation is discharged from the bottom of the flash tank;

[0013] S5: The rich amine liquid discharged from the bottom of the flash tank enters the regeneration tower for regeneration, and the nitrogen tank inputs nitrogen into the rich amine liquid discharged from the regeneration tower and the flash tank respectively. The rich amine liquid entering the regeneration tower is discharged from the upper end of the regeneration tower riser and is heated. The heated rich amine liquid enters the lower end of the regeneration tower riser to continue regeneration;

[0014] S6: The amine-rich liquid after regeneration in the regeneration tower becomes a semi-lean liquid. The semi-lean liquid is discharged from the bottom of the regeneration tower and divided into two paths. One path circulates into the regeneration tower, and the other path enters the absorption tower to continue to adsorb CO2. The regenerated gas in the regeneration tower is discharged from the top of the regeneration tower. After passing through the regeneration gas cooler, the temperature of the regeneration gas is reduced from 50-60°C to 30-40°C. The regeneration gas after cooling enters the regeneration gas-liquid separator for gas-liquid separation. The separated solution is discharged from the bottom of the regeneration gas-liquid separator and enters the top of the regeneration tower for recycling. The separated CO2 is discharged from the top of the regeneration gas-liquid separator and enters the gas storage tank.

[0015] The working principle of the present invention is that the furnace top gas enters the compressor for pressurization after three dust removals, and while pressurizing, liquid soft water is sprayed to cool the compressor. The pressurized furnace top gas and the sprayed soft water are discharged from the compressor together and enter the compressor gas-liquid separator together. The separated liquid enters the liquid soft water cooler, and the furnace top gas enters the absorption tower to absorb CO2. The amine liquid rich liquid that has absorbed CO2 enters the flash tank for flash evaporation. The amine liquid rich liquid after flash evaporation enters the regeneration tower. The nitrogen tank inputs nitrogen into the amine liquid rich liquid discharged from the flash tank to dilute the density of the amine liquid rich liquid. At the same time, nitrogen is input into the regeneration tower to regenerate amine liquid lean liquid. The regeneration tower is divided into two parts, an upper filler and a lower filler, by a riser tray. The upper filler of the regeneration tower is filled with The material is decomposed into countless droplets, CO2 is regenerated in the upper packing of the regeneration tower, and the rich liquid flows by gravity to the riser tray in the middle of the regeneration tower and is collected in the tray. In the process, the amine liquid rich liquid is heated by the reboiler or slag flushing water. The rich liquid after preliminary stripping becomes semi-lean liquid and is discharged from the bottom of the regeneration tower and divided into two streams: one stream is pressurized by a semi-lean liquid pump, cooled by a semi-lean liquid heat exchanger and a semi-lean liquid air cooler, and then sent to the middle of the absorption tower; the other stream is pressurized by a semi-lean liquid pump, filtered by a semi-lean liquid filter, and sent to the regeneration tower for further regeneration, and finally becomes lean liquid and enters the regeneration tower. After the reducing gas entering the gas heating furnace is heated, it is evenly sprayed into the hydrogen-rich carbon circulating oxygen blast furnace through 30 air outlets.

[0016] The beneficial effects of the present invention are as follows: as the core technology of large-scale hydrogen-rich carbon circulating oxygen blast furnace (HyCROF), the method can solve the problem of 400m 3 The hydrogen-rich carbon circulating oxygen blast furnace decarburization technology is promoted to large blast furnaces, suitable for large and medium-sized blast furnaces to process 200,000-450,000 Nm 3 / h of decarbonized coal gas, and reduce the CO2 content of the reducing gas injected into large and medium-sized hydrogen-rich carbon-circulating oxygen blast furnaces to below 3%, meeting the needs of large and medium-sized hydrogen-rich carbon-circulating oxygen blast furnaces to reduce carbon emissions, reduce solid fuel consumption, reduce energy consumption, and improve efficiency.

[0017] Solution 2, which is the preferred basic solution, the specific process of the three groups of dust removal steps in step S1 is as follows:

[0018] 1) Perform rough dust removal to reduce the dust content in the top gas from 60g / Nm 3 Reduced to 60mg / Nm 3 ;

[0019] 2) After rough dust removal, dry dust removal is carried out to reduce the dust content in the top gas from 60mg / Nm 3 Reduce to 5-10mg / Nm 3 ;

[0020] 3) After dry dust removal, fine dust removal is carried out to reduce the dust content in the top gas from 5-10mg / Nm 3 Reduce to ≤2mg / Nm 3 .

[0021] Option three is the preferred basic option. In step S2, the top gas after fine dust removal and cooling enters the compressor. The compressor increases the pressure of the top gas from 150-200Kpa to 1000-1700Kpa. During the pressurization process, the compressor temperature is 350°C, and the spray soft water temperature is 25°C. After heat exchange and cooling by spray soft water, the temperature of the top gas leaving the compressor is reduced from 300-350°C to ≤40°C.

[0022] Scheme 4 is the preferred basic scheme. The equipment small cycle and equipment large cycle in step S2 are as follows:

[0023] Equipment small circulation: When the hydrogen-rich carbon circulating oxygen blast furnace stops or the purified gas needs to reduce load, the equipment is stopped, the emergency circulation valve is opened, and the compressed gas and spray soft water enter the gas main through the emergency circulation pipe 1, and circulate along the route of gas main → compressor → emergency circulation pipe 1 → gas main. After the equipment fault is cleared, the normal line operation is restored;

[0024] The equipment has a large circulation. When the equipment has a fault such as pipeline blockage or excessive pressure, the equipment will be stopped and the emergency circulation valve 2 will be opened. The compressed gas and spray soft water will enter the gas dust removal pipe from the emergency circulation pipe 2 and circulate along the route of gas dust removal pipe → fine dust removal device → gas main → compressor → emergency circulation pipe 2 → gas dust removal pipe. After the equipment fault is cleared, the normal line operation will be restored.

[0025] In the hydrogen-rich carbon cycle oxygen blast furnace decarbonization system, three compressors are used in parallel compression, and the gas processing capacity of each compressor is 70000Nm 3 , then a total of 210000Nm 3 When the gas processing capacity of the hydrogen-rich carbon circulating oxygen blast furnace stops or the purified gas needs to be reduced, the emergency circulation valve 1 can be opened to start a small circulation to stabilize the compressor output gas pressure. When the other equipment stops running, the emergency circulation valve 2 can be opened to start a large circulation to keep the compressor running at high pressure without interruption, so as to reduce the start and stop times of the compressor high-voltage motor and protect the high-voltage motor.

[0026] Scheme 5 is a preferred basic scheme. In step S5, the nitrogen tank inputs nitrogen with a pressure of 200-300 KPa into the amine rich liquid, thereby raising the amine rich liquid from bottom to top to the top of the regeneration tower.

[0027] Scheme six, which is the preferred basic scheme, the heating method in step S5 is reboiler heating, the amine rich liquid discharged from the upper end of the regeneration tower riser pipe enters the reboiler, the steam supply device inputs steam into the reboiler, the amine rich liquid exchanges heat with the steam, and the temperature of the amine rich liquid is heated from 65-68°C to 70-78°C, and the heated amine rich liquid is discharged from the bottom of the reboiler and enters the lower end of the regeneration tower.

[0028] Scheme 7, which is the preferred basic scheme, in step S6, the semi-lean liquid discharged from the bottom of the regeneration tower is divided into two paths in the following specific manner:

[0029] The pressure of the semi-lean liquid is increased from 200Kpa to 500Kpa by the filter circulation pump, and then the mechanical and physical impurities are removed by the semi-lean liquid filter. The semi-lean liquid after impurities are removed enters the bottom of the regeneration tower for recycling;

[0030] The semi-lean liquid is pressurized by the semi-lean liquid pump, increasing the hydraulic pressure of the semi-lean liquid from 200Kpa to 1400Kpa. The pressurized semi-lean liquid enters the air cooler for cooling, reducing the temperature of the semi-lean liquid from 60-68℃ to 48-58℃. The cooled semi-lean liquid enters the absorption tower for recycling.

[0031] Scheme 8 is a preferred embodiment of Scheme 7. In step S6, the solution in the solution storage tank is mixed with the solution separated from the regeneration gas-liquid separator, and the two are then fed into the regeneration tower for use. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a structural schematic diagram of a method for decarbonization of a large-scale gasification device of a hydrogen-rich carbon circulating oxygen blast furnace according to the present invention. DETAILED DESCRIPTION

[0033] The present invention is further described in detail below through specific embodiments:

[0034] The reference numerals in the drawings of the specification include: 1. Hydrogen-rich carbon circulation oxygen blast furnace, 2. Compressor, 3. Liquid spray soft water cooler, 4. Compressor gas-liquid separator, 5. Liquid spray soft water heat exchanger, 6. Absorption tower, 7. Gas heating furnace, 8. Flash tank, 9. Gas pipeline network, 10. Regeneration tower, 11. Nitrogen tank, 12. Emergency circulation valve 1, 13. Emergency circulation valve 2, 14. Regeneration gas cooler, 15. Regeneration gas liquid separator , 16. Gas storage tank, 17. Emergency circulation pipe 1, 18. Gas main, 19. Emergency circulation pipe 2, 20. Solution storage tank, 21. Air cooler, 22. Gas dust removal pipe, 23. Semi-lean liquid pump, 24. Reboiler, 25. Steam supply device, 26. Filter circulation pump, 27. Semi-lean liquid filter, 28. Purified gas separation tank, 29. Gas heater, 30. Expander, 31. Four-valve group, 32. Three-valve group.

[0035] Example

[0036] The embodiment is basically as shown in the attached Figure 1 As shown: A method for decarbonizing a large-scale gasification device of a hydrogen-rich carbon circulating oxygen blast furnace, the steps of the decarbonization method are as follows:

[0037] S1: The top gas of the hydrogen-rich carbon circulating oxygen blast furnace is divided into two routes. One route is dedusted and cooled by three groups of dust removal processes, and the temperature of the top gas is reduced from 120-300℃ to ≤40℃. The top gas after dust removal and cooling enters the compressor, and the other route enters the flash gas pipeline after passing through the four-valve group. The specific process of the three groups of dust removal processes is as follows:

[0038] 1) Perform rough dust removal to reduce the dust content in the top gas from 60g / Nm 3 Reduced to 60mg / Nm 3 ;

[0039] 2) After rough dust removal, dry dust removal is carried out to reduce the dust content in the top gas from 60mg / Nm 3 Reduce to 5-10mg / Nm 3 ;

[0040] 3) After dry dust removal, fine dust removal is carried out to reduce the dust content in the top gas from 5-10mg / Nm 3 Reduce to ≤2mg / Nm 3 ;

[0041] The furnace top gas after dust removal and temperature reduction enters compressor 2;

[0042] S2: Compressor 2 pressurizes the furnace top gas, and the soft water sprayed in the soft water spray cooler 3 cools down the compressor 2. The furnace top gas after fine dust removal and cooling enters compressor 2. Compressor 2 pressurizes the furnace top gas from 150-200Kpa to 1300-1600Kpa. During the pressurization process, the compressor 2 is cooled by the 25℃ soft water spray temperature, and the temperature of compressor 2 is reduced from 350℃ to ≤40℃. The compressed gas after compression and cooling is discharged from compressor 2 together with the soft water spray, and it is judged whether to start the emergency circulation mode according to the operation status of the decarbonization system:

[0043] When the decarbonization system is operating normally, the emergency circulation valve 12 and the emergency circulation valve 2 13 are closed, and the compressed gas and the sprayed soft water enter the compressor gas-liquid separator 4 for gas-liquid separation. The separated furnace top gas is discharged from the top of the compressor gas-liquid separator 4, and the liquid is discharged from the bottom of the compressor gas-liquid separator 4;

[0044] When the decarbonization system fails, open the emergency circulation valve 12 or the emergency circulation valve 2 13 to start the equipment small circulation or equipment large circulation. The details of the equipment small circulation and equipment large circulation are as follows:

[0045] Equipment small circulation: When the hydrogen-rich carbon circulating oxygen blast furnace 1 stops or the purified gas needs to be unloaded, the equipment is stopped, the emergency circulation valve 12 is opened, and the compressed gas and the sprayed soft water enter the gas main 18 through the emergency circulation pipe 17, and circulate along the route of gas main 18 → compressor 2 → emergency circulation pipe 17 → gas main 18. After the equipment fault is cleared, the normal line operation is restored;

[0046] Equipment large circulation, when the equipment has pipeline blockage, excessive pressure and other faults, the equipment is stopped, the emergency circulation valve 2 13 is opened, and the compressed gas and spray soft water enter the gas dust removal pipe 22 from the emergency circulation pipe 2 19, and circulate along the route of gas dust removal pipe 22 → fine dust removal → gas main 18 → compressor 2 → emergency circulation pipe 2 19 → gas dust removal pipe 22. After the equipment fault is cleared, the normal line operation is restored;

[0047] S3: the liquid discharged from the compressor gas-liquid separator 4 enters the liquid spray soft water heat exchanger 5, the top gas discharged from the compressor gas-liquid separator 4 enters the lower part of the absorption tower 6, and is mixed with the amine liquid lean liquid in the absorption tower 6. The amine liquid lean liquid absorbs CO2 in the top gas to form amine liquid rich liquid. The top gas absorbs CO2 to form purified gas. The amine liquid rich liquid is discharged from the bottom of the absorption tower 6, and the purified gas is discharged from the top of the absorption tower 6.

[0048] S4: The purified gas discharged from the top of the absorption tower (6) is divided into two paths. One path first enters the gas heater 16 to heat the temperature from 40-50°C to 80-100°C, and then enters the expander 21 to reduce the pressure after heating. The purified gas after decompression enters the purified gas separation tank 28. The other path passes through the three-valve group 32 to reduce the pressure of the purified gas from 1300-1600Kpa to 350-500Kpa, and then enters the purified gas separation tank 28 and enters the gas heating furnace 7. The amine liquid rich liquid discharged from the bottom of the absorption tower 6 enters the flash tank 8 for flash evaporation. The flash steam after flash evaporation is discharged from the top of the flash tank 8 and enters the gas pipe network 9 together with the furnace top gas after decompression by the four-valve group 31. The amine liquid rich liquid after flash evaporation is discharged from the bottom of the flash tank 8;

[0049] S5: the rich amine liquid discharged from the bottom of the flash tank 8 enters the regeneration tower 10 for regeneration, the nitrogen tank 11 inputs nitrogen into the regeneration tower 10 and the rich amine liquid discharged from the flash tank 8 respectively, the nitrogen tank 11 inputs nitrogen with a pressure of 200-300Kpa into the rich amine liquid, so that the rich amine liquid rises from bottom to top to the top of the regeneration tower 10, the rich amine liquid entering the regeneration tower 10 is discharged from the upper end of the regeneration tower 10 rising gas pipe, and is heated by the reboiler 24, the rich amine liquid discharged from the upper end of the regeneration tower 10 rising gas pipe enters the reboiler 24, the steam supply device 25 inputs steam into the reboiler 24, the rich amine liquid exchanges heat with the steam, and the temperature of the rich amine liquid is heated from 65-68°C to 70-78°C, the heated rich amine liquid is discharged from the bottom of the reboiler 24, and enters the lower end of the regeneration tower 10 rising gas pipe to continue regeneration;

[0050] S6: The amine-rich liquid after regeneration in the regeneration tower 10 becomes a semi-lean liquid. The semi-lean liquid is discharged from the bottom of the regeneration tower (10) and divided into two paths. One path circulates into the regeneration tower 10, and the other path enters the absorption tower 6 to continue to adsorb CO2. The specific method of dividing the semi-lean liquid discharged from the bottom of the regeneration tower 10 into two paths is as follows:

[0051] The semi-lean liquid is pressurized by the filter circulation pump 26 from 200Kpa to 500Kpa, and then the semi-lean liquid filter 27 removes mechanical and physical impurities. The semi-lean liquid after impurities removal enters the bottom of the regeneration tower 10 for recycling;

[0052] The semi-lean liquid is pressurized by the semi-lean liquid pump 23 from 200Kpa to 1400Kpa. The pressurized semi-lean liquid enters the air cooler 21 for cooling, and the temperature of the semi-lean liquid is reduced from 60-68°C to 48-58°C. The cooled semi-lean liquid enters the absorption tower 6 for recycling.

[0053] The regenerated gas in the regeneration tower 10 is discharged from the top of the regeneration tower 10, and passes through the regeneration gas cooler 14 to reduce the temperature of the regeneration gas from 50-60°C to 30-40°C. The cooled regeneration gas enters the regeneration gas gas-liquid separator 15 for gas-liquid separation, and the separated solution is discharged from the bottom of the regeneration gas gas-liquid separator 15 and enters the regeneration tower 10 for recycling. The separated CO2 is discharged from the top of the regeneration gas gas-liquid separator 15 and enters the gas storage tank 16. The solution in the solution storage tank 20 is mixed with the solution separated in the regeneration gas gas-liquid separator 15, and enters the regeneration tower 10 together for utilization.

[0054] The implementation method of this embodiment is:

[0055] First, the top gas of the hydrogen-rich carbon circulating oxygen blast furnace 1 is subjected to three groups of dust removal processes for dust removal and cooling, and the temperature of the top gas is reduced from 120°C to ≤40°C. The specific process of the three groups of dust removal processes is as follows:

[0056] 1) Perform rough dust removal to reduce the dust content in the top gas from 60g / Nm 3 Reduced to 60mg / Nm 3 ;

[0057] 2) After rough dust removal, dry dust removal is carried out to reduce the dust content in the top gas from 60mg / Nm 3 Reduce to 5-10mg / Nm 3 ;

[0058] 3) After dry dust removal, fine dust removal is carried out to reduce the dust content in the top gas from 5-10mg / Nm 3 Reduce to ≤2mg / Nm 3 ;

[0059] The top gas after dust removal and cooling enters compressor 2; compressor 2 pressurizes the top gas, and the soft water sprayed in the soft water spray cooler 3 cools compressor 2. The top gas after fine dust removal and cooling enters compressor 2, and compressor 2 pressurizes the top gas from 150-200Kpa to 1300-1600Kpa. During the pressurization process, the compressor 2 is cooled by the 25℃ soft water spray temperature, and the temperature of compressor 2 is reduced from 350℃ to ≤40℃. The compressed gas after compression and cooling is discharged from compressor 2 together with the soft water spray, and it is judged whether to start the emergency circulation mode according to the operation status of the decarbonization system:

[0060] When the decarbonization system is operating normally, the emergency circulation valve 12 and the emergency circulation valve 2 13 are closed, and the compressed gas and the sprayed soft water enter the compressor gas-liquid separator 4 for gas-liquid separation. The separated furnace top gas is discharged from the top of the compressor gas-liquid separator 4, and the liquid is discharged from the bottom of the compressor gas-liquid separator 4;

[0061] When the decarbonization system fails, open the emergency circulation valve 12 or the emergency circulation valve 2 13 to start the equipment small circulation or equipment large circulation. The details of the equipment small circulation and equipment large circulation are as follows:

[0062] Equipment small circulation: When the hydrogen-rich carbon circulating oxygen blast furnace 1 stops or the purified gas needs to be unloaded, the equipment is stopped, the emergency circulation valve 12 is opened, and the compressed gas and the sprayed soft water enter the gas main 18 through the emergency circulation pipe 17, and circulate along the route of gas main 18 → compressor 2 → emergency circulation pipe 17 → gas main 18. After the equipment fault is cleared, the normal line operation is restored;

[0063] The equipment has a large circulation. When the equipment has a pipeline blockage, excessive pressure or other faults, the equipment is stopped and the emergency circulation valve 13 is opened. The compressed gas and spray soft water enter the gas dust removal pipe 22 from the emergency circulation pipe 19, and circulate along the route of gas dust removal pipe 22 → fine dust removal → gas main pipe 18 → compressor 2 → emergency circulation pipe 19 → gas dust removal pipe 22. After the equipment fault is cleared, the normal line operation is restored. The liquid discharged from the compressor gas-liquid separator 4 enters the spray soft water heat exchanger 5, and the top gas discharged from the compressor gas-liquid separator 4 enters the lower part of the absorption tower 6 and is mixed with the amine lean liquid in the absorption tower 6. The amine liquid The lean liquid absorbs CO2 in the furnace top gas to form an amine liquid rich liquid. The furnace top gas absorbs CO2 to form a purified gas. The amine liquid rich liquid is discharged from the bottom of the absorption tower 6, and the purified gas is discharged from the top of the absorption tower 6. It enters the purified gas separation tank 28 for gas-liquid separation. The separated gas enters the gas pipeline 9, enters the gas heater 29 for heating, and then enters the expander 30 for decompression. The decompressed gas enters the purified gas separation tank 28 for separation, and then enters the gas heater 29; the purified gas discharged from the top of the absorption tower 6 enters the purified gas separation tank 28 for gas-liquid separation, and the separated gas enters the gas heating furnace 7. The amine liquid rich liquid is discharged from the bottom of the absorption tower 6. The liquid-rich liquid enters the flash tank 8 for flash evaporation, and the flash steam after flash evaporation is discharged from the top of the flash tank 8 and enters the gas pipe network 9. The amine liquid-rich liquid after flash evaporation is discharged from the bottom of the flash tank 8; the amine liquid-rich liquid discharged from the bottom of the flash tank 8 enters the regeneration tower 10 for regeneration, and at the same time, the nitrogen tank 11 inputs nitrogen into the amine liquid-rich liquid for pressurization. The nitrogen tank 11 inputs nitrogen with a pressure of 200-300Kpa into the amine liquid-rich liquid, so that the amine liquid-rich liquid rises from bottom to top to the top of the regeneration tower 10. The amine liquid-rich liquid entering the regeneration tower 10 is discharged from the upper end of the regeneration tower 10 gas pipe and is heated. The heating method is heating by the reboiler 24. The regeneration tower 10 gas pipe The amine rich liquid discharged from the upper end enters the reboiler 24, and the steam supply device 25 inputs steam into the reboiler 24. The amine rich liquid exchanges heat with the steam to heat the temperature of the amine rich liquid from 65-68°C to 70-78°C. The heated amine rich liquid is discharged from the bottom of the reboiler 24 and enters the lower end of the regeneration tower 10 riser pipe to continue regeneration; the amine rich liquid regenerated by the regeneration tower 10 becomes a semi-lean liquid, which is discharged from the bottom of the regeneration tower 10 and divided into two paths, one of which circulates into the regeneration tower 10, and the other enters the absorption tower 6 to continue adsorbing CO2. The specific method of dividing the semi-lean liquid discharged from the bottom of the regeneration tower 10 into two paths is as follows:

[0064] The semi-lean liquid is pressurized by the filter circulation pump 26 from 200Kpa to 500Kpa, and then the semi-lean liquid filter 27 removes mechanical and physical impurities. The semi-lean liquid after impurities removal enters the bottom of the regeneration tower 10 for recycling;

[0065] The semi-lean liquid is pressurized by the semi-lean liquid pump 23 from 200Kpa to 1400Kpa. The pressurized semi-lean liquid enters the air cooler 21 for cooling, and the temperature of the semi-lean liquid is reduced from 60-68°C to 48-58°C. The cooled semi-lean liquid enters the absorption tower 6 for recycling. The regenerated gas in the regeneration tower 10 is discharged from the top of the regeneration tower 10, and passes through the regeneration gas cooler 14 to reduce the temperature of the regeneration gas from 50-60°C to 30-40°C. The cooled regeneration gas enters the regeneration gas-liquid separator 15 for gas-liquid separation. The separated solution is discharged from the bottom of the regeneration gas-liquid separator 15 and enters the regeneration tower 10 for recycling. The separated CO2 is discharged from the top of the regeneration gas-liquid separator 15 and enters the gas storage tank 16. The solution in the solution storage tank 20 is mixed with the solution separated in the regeneration gas-liquid separator 15, and enters the regeneration tower 10 together for utilization.

[0066] The above is only an embodiment of the present invention, and the common knowledge such as the known specific structure and characteristics in the scheme is not described in detail here. It should be pointed out that for those skilled in the art, several deformations and improvements can be made without departing from the structure of the present invention, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A method for decarbonization of a large-scale gasification device for a hydrogen-rich carbon circulating oxygen blast furnace, characterized in that: The following steps are involved: S1: The top gas of the hydrogen-rich carbon circulating oxygen blast furnace (1) is divided into two paths. One path is subjected to three groups of dust removal processes for dust removal and cooling, and the temperature of the top gas is reduced from 120-300°C to ≤40°C. The top gas after dust removal and cooling enters the compressor (2), and the other path enters the flash gas pipeline after passing through a four-valve group; S2: The compressor (2) pressurizes the furnace top gas, and the soft water in the soft water cooler (3) cools the compressor (2). The compressed gas and the soft water are discharged from the compressor (2) after compression and cooling, and it is determined whether to start the emergency circulation mode according to the operation status of the decarbonization system: When the decarbonization system operates normally, the emergency circulation valve 1 (12) and the emergency circulation valve 2 (13) are closed, and the compressed coal gas and the sprayed soft water enter the compressor gas-liquid separator (4) for gas-liquid separation, and the separated furnace top gas is discharged from the top of the compressor gas-liquid separator (4), and the liquid is discharged from the bottom of the compressor gas-liquid separator (4); When the decarbonization system fails, open the emergency circulation valve 1 (12) or the emergency circulation valve 2 (13) to start the equipment small circulation or equipment large circulation; S3: the liquid discharged from the compressor gas-liquid separator (4) enters the liquid spray soft water heat exchanger (5), the furnace top gas discharged from the compressor gas-liquid separator (4) enters the lower part of the absorption tower (6), and is mixed with the amine liquid lean liquid in the absorption tower (6), the amine liquid lean liquid absorbs CO2 in the furnace top gas to form amine liquid rich liquid, the furnace top gas absorbs CO2 to form purified gas, the amine liquid rich liquid is discharged from the bottom of the absorption tower (6), and the purified gas is discharged from the top of the absorption tower (6); S4: The purified gas discharged from the top of the absorption tower (6) is divided into two paths. One path first enters the coal gas heater (16) to heat the temperature from 40-50°C to 80-100°C, and then enters the expander (21) to reduce the pressure after heating. The purified gas after decompression enters the purified gas separation tank (28). The other path passes through the three-valve group (32) to reduce the pressure of the purified gas from 1300-1600Kpa to 350-500Kpa, and then enters the purified gas separation tank (28) and then enters the coal gas heating furnace (7). The rich amine liquid discharged from the bottom of the absorption tower (6) enters the flash tank (8) for flash evaporation. The flash steam after flash evaporation is discharged from the top of the flash tank (8) and enters the coal gas network (9) together with the coal gas from the furnace top after decompression by the four-valve group (31). The rich amine liquid after flash evaporation is discharged from the bottom of the flash tank (8); S5: the rich amine liquid discharged from the bottom of the flash tank (8) enters the regeneration tower (10) for regeneration, the nitrogen tank (11) inputs nitrogen into the regeneration tower (10) and the rich amine liquid discharged from the flash tank (8), respectively, the rich amine liquid entering the regeneration tower (10) is discharged from the upper end of the riser pipe of the regeneration tower (10), and after being heated, the heated rich amine liquid enters the lower end of the riser pipe of the regeneration tower (10) for further regeneration; S6: After regeneration in the regeneration tower (10), the rich amine liquid becomes a semi-lean liquid. The semi-lean liquid is discharged from the bottom of the regeneration tower (10) and divided into two paths. One path circulates into the regeneration tower (10), and the other path enters the absorption tower (6) to continue to adsorb CO2. The regenerated gas in the regeneration tower (10) is discharged from the top of the regeneration tower (10). After passing through the regeneration gas cooler (14), the temperature of the regeneration gas is reduced from 50-60°C to 30-40°C. The regeneration gas after cooling enters the regeneration gas-liquid separator (15) for gas-liquid separation. The separated solution is discharged from the bottom of the regeneration gas-liquid separator (15) and enters the regeneration tower (10) for recycling. The separated CO2 is discharged from the top of the regeneration gas-liquid separator (15) and enters the gas storage tank (16).

2. The method for decarbonization of a large-scale gasification device for a hydrogen-rich carbon cycle oxygen blast furnace according to claim 1, characterized in that: The specific process of the three groups of dust removal steps in step S1 is as follows: 1) Perform rough dust removal to reduce the dust content in the top gas from 60g / Nm 3 Reduced to 60mg / Nm 3 ; 2) After rough dust removal, dry dust removal is carried out to reduce the dust content in the top gas from 60mg / Nm 3 Reduce to 5-10mg / Nm 3 ; 3) After dry dust removal, fine dust removal is carried out to reduce the dust content in the top gas from 5-10mg / Nm 3 Reduce to ≤2mg / Nm 3 .

3. The method for decarbonization of a large-scale gasification device for a hydrogen-rich carbon cycle oxygen blast furnace according to claim 1, characterized in that: In step S2, the furnace top gas after fine dust removal and cooling enters the compressor (2), and the compressor (2) increases the pressure of the furnace top gas from 150-200 KPa to 1300-1600 KPa. During the pressurization process, the compressor (2) is cooled by spraying soft water at a temperature of 25°C, and the temperature of the compressor (2) is reduced from 350°C to ≤40°C.

4. The method for decarbonization of a large-scale gasification device of a hydrogen-rich carbon circulating oxygen blast furnace according to claim 1, characterized in that: The equipment small cycle and equipment large cycle in step S2 are as follows: Equipment small circulation: When the hydrogen-rich carbon circulating oxygen blast furnace (1) stops or the purified gas needs to reduce the load, the equipment is stopped, the emergency circulation valve 1 (12) is opened, and the compressed gas and the spray soft water enter the gas main (18) through the emergency circulation pipe 1 (17), and circulate along the route of gas main (18) → compressor (2) → emergency circulation pipe 1 (17) → gas main (18). After the equipment fault is cleared, the normal line operation is restored; The equipment has a large circulation. When the equipment has a fault such as pipeline blockage or excessive pressure, the equipment is stopped and the emergency circulation valve 2 (13) is opened. The compressed gas and spray soft water enter the gas dust removal pipe (22) through the emergency circulation pipe 2 (19) and circulate along the route of gas dust removal pipe (22) → fine dust removal → gas main pipe (18) → compressor (2) → emergency circulation pipe 2 (19) → gas dust removal pipe (22). After the equipment fault is cleared, normal line operation is restored.

5. The method for decarbonization of a large-scale gasification device for a hydrogen-rich carbon circulating oxygen blast furnace according to claim 1, characterized in that: In step S5, the nitrogen tank (11) inputs nitrogen with a pressure of 200-300 KPa into the amine rich liquid, thereby raising the amine rich liquid from bottom to top to the top of the regeneration tower (10).

6. The method for decarbonization of a large-scale gasification device for a hydrogen-rich carbon cycle oxygen blast furnace according to claim 1, characterized in that: The heating method in step S5 is heating by a reboiler (24). The amine rich liquid discharged from the upper end of the riser pipe of the regeneration tower (10) enters the reboiler (24). The steam supply device (25) inputs steam into the reboiler (24). The amine rich liquid exchanges heat with the steam to heat the amine rich liquid from 65-68° C. to 70-78° C. The heated amine rich liquid is discharged from the bottom of the reboiler (24) and enters the lower end of the regeneration tower (10).

7. The method for decarbonization of a large-scale gasification device for a hydrogen-rich carbon cycle oxygen blast furnace according to claim 1, characterized in that: In step S6, the semi-lean liquid discharged from the bottom of the regeneration tower (10) is divided into two paths in the following specific manner: The semi-lean liquid is pressurized by the filter circulation pump (26) from 200Kpa to 500Kpa, and then the semi-lean liquid is filtered by the semi-lean liquid filter (27) to remove mechanical and physical impurities. The semi-lean liquid after the impurities are removed enters the bottom of the regeneration tower (10) for recycling; The semi-lean liquid is pressurized by the semi-lean liquid pump (23) from 200 KPa to 1400 KPa. The pressurized semi-lean liquid enters the air cooler (21) for cooling, and the temperature of the semi-lean liquid is reduced from 60-68°C to 48-58°C. The cooled semi-lean liquid enters the absorption tower (6) for recycling.

8. The method for decarbonization of a large-scale gasification device for a hydrogen-rich carbon cycle oxygen blast furnace according to claim 7, characterized in that: In step S6, the solution in the solution storage tank (20) is mixed with the solution separated in the regeneration gas-liquid separator (15), and the two are then fed into the regeneration tower (10) for use.

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