Device for improving decarburization effect of hydrogen-rich carbon circulation oxygen blast furnace gas flash tank
By introducing nitrogen and steam systems into the flash tank of a hydrogen-rich carbon circulating oxygen blast furnace, the partial pressure of CO2 and the temperature of steam is increased, the problem of low CO2 resolution in the prior art is solved, and efficient CO2 capture is achieved and energy consumption is reduced.
Patent Information
- Application Number
- CN202421012602.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-11
- Publication Date
- 2025-02-21
- Estimated Expiration
- 2034-05-11
AI Technical Summary
In the existing hydrogen-rich carbon circulating oxygen blast furnace gas decarbonization process, it is difficult for the CO2 content in the purified gas to meet the design standards, resulting in low CO2 resolution and high energy consumption.
By introducing nitrogen and steam systems into the flash tank, the partial pressure of CO2 is reduced, and the heat loss caused by the nitrogen inflow is compensated by heating the steam, thereby improving the resolution of CO2.
The resolution rate of CO2 is significantly improved and the energy consumption of hydrogen-rich carbon circulating oxygen blast furnace gas carbon dioxide capture process is reduced.
Smart Images
Figure CN222512902U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a device for improving the decarburization effect of a hydrogen-rich carbon circulating oxygen blast furnace gas flash tank. Background Art
[0002] The hydrogen-rich carbon circulating oxygen blast furnace (HyCROF) is a smelting process that uses oxygen blast instead of traditional heated air blast. The amine method is used to remove CO2. In the existing technology, the designed flash gas volume in the flash tank is 9200Nm³ / h, and the actual volume is 500Nm³ / h. The designed purified gas CO2 content is less than 3%, and the actual average is 3.45%. During operation, the purified gas CO2 content fluctuates between 3% and 10%. The designed CO2 removal volume is 105800Nm³ / h, and the actual volume is 65000Nm³ / h. When the CO2 content is high, it is difficult for the CO2 content in the purified gas to reach the standard of not more than 3%. Therefore, how to improve the CO2 resolution rate is a technical problem that urgently needs to be solved in the hydrogen-rich carbon circulating oxygen blast furnace coal gas decarbonization process to purify the reducing gas and remove CO2 from the raw gas. Summary of the invention
[0003] The purpose of the utility model is to provide a device for improving the decarbonization effect of a hydrogen-rich carbon circulating oxygen blast furnace gas flash tank, thereby increasing the amount of flash gas in the flash tank during operation, reducing the load of the regeneration tower, and greatly improving the efficiency of the CO2 regeneration process, which can greatly reduce the energy consumption of the current hydrogen-rich carbon circulating oxygen blast furnace gas carbon dioxide capture process.
[0004] The technical solution adopted by the utility model is a device for improving the decarburization effect of a hydrogen-rich carbon circulating oxygen blast furnace gas flash tank, comprising an absorption tower, a flash tank, a regeneration tower, a nitrogen system and a steam system, wherein the flash tank is connected to the absorption tower, and the lower part of the absorption tower is connected to a raw gas inlet pipe, wherein the raw gas is hydrogen-rich carbon circulating oxygen blast furnace top gas, and the pressure of the raw gas entering the absorption tower is 1.5-1.7Mpa, and the nitrogen pipe of the nitrogen system is connected to the purge port of the flash tank, and the high-pressure nitrogen input to the flash tank is controlled The steam pressure is controlled at 0.6-0.8MPa, and the nitrogen pipe is DN150; the steam pipe of the steam system is connected to the purge port of the flash tank, the steam pressure is controlled at 0.4-0.6MPa, and the steam pipe is DN400; the outlet of the flash tank is provided with a double-line parallel exhaust pipeline; the flash tank is connected to the regeneration tower through the bottom rich liquid pipe, the nitrogen pipe is connected to the bottom rich liquid pipe, the nitrogen gas lift pressure input by the nitrogen pipe is controlled at 0.6-0.8MPa, and the nitrogen pipe is DN65.
[0005] The raw gas of the top gas of the hydrogen-rich carbon cycle oxygen blast furnace uses an absorption tower that enters from the bottom, and contacts the MDEA alcohol amine solution from top to bottom in the tower body, so as to capture most of the CO2 in the hydrogen-rich carbon cycle oxygen blast furnace gas, enter the alcohol amine solution, absorb the CO2 acid gas lean liquid in the absorption tower to become rich liquid, and enter the flash tank for flash evaporation. When the alcohol amine rich liquid enters the flash tank, high-pressure nitrogen is input through the nitrogen system nitrogen pipe to rapidly increase the pressure in the tank. At this time, the second exhaust pipeline is added to reduce the pressure in the tank to a lower level. Due to the introduction of nitrogen, the CO2 partial pressure is kept low. Therefore, when the pressure in the flash tank reaches a certain value, the CO2 partial pressure of the alcohol amine rich liquid will be lower than the pressure in the tank. At this time, the CO2 in the alcohol amine rich liquid will be rapidly precipitated and converted into gaseous substances. At the same time, high-temperature and high-pressure steam is input into the flash tank through the steam pipe of the steam system, so that the pressure in the tank increases rapidly, and the temperature also increases at the same time, compensating for the temperature loss caused by the introduction of nitrogen. At this time, the saturated vapor pressure of the alcoholamine rich liquid also increases accordingly, but due to the low temperature of the alcoholamine rich liquid when nitrogen is introduced, its saturated vapor pressure is still low. Therefore, when the pressure in the tank reaches a certain value, the saturated vapor pressure of the alcoholamine rich liquid will be lower than the pressure in the tank. At this time, the alcoholamine rich liquid will evaporate rapidly and be converted into gaseous substances, thereby reducing the CO2 partial pressure, so that the CO2 dissolved in the alcoholamine rich liquid can be resolved. Reduce the total pressure of the flash tank, set a double-line parallel pipeline at the outlet pipeline of the flash tank, increase the flow rate of flash analysis gas, and finally reduce the total pressure on the top of the flash tank. After the pressure of the flash tank is reduced, the nitrogen gas of the nitrogen pipe system from the alcoholamine rich liquid to the regeneration tower is further used to lift the alcoholamine rich liquid at the bottom of the flash tank to the regeneration tower, and complete the regeneration of CO2 gas in the regeneration tower.
[0006] The high-pressure nitrogen input into the flash tank by the nitrogen pipe of the nitrogen system is controlled at 0.6-0.8MPa. The nitrogen pipe is DN150 and enters from the purge port of the flash tank. It is also equipped with a flow meter, a pressure transmitter, a flow regulating valve, a check valve, and a manual stop valve.
[0007] The steam pipe of the steam system is connected to the opening on the pipeline in front of the steam temperature and pressure reducing valve. The steam pressure is controlled at 0.4-0.6MPa. The steam pipe is DN400 and is introduced from the purge port of the flash tank. It is also equipped with a flow meter, thermocouple, pressure transmitter, steam flow regulating valve, check valve, front and rear manual stop valves, and steam trap.
[0008] The flash tank outlet double-line parallel pipeline is additionally provided with a second exhaust pipeline with a pipe diameter of DN300. The pipeline is equipped with a flow meter, a thermocouple, a pressure transmitter, a check valve, a flow regulating valve, and front and rear manual valves.
[0009] The nitrogen gas lift pressure input by the nitrogen pipe of the nitrogen pipe system from the alcoholamine rich liquid to the regeneration tower is controlled at 0.6-0.8MPa. The nitrogen pipe is DN65 and is introduced from the bottom pipeline from the alcoholamine rich liquid to the regeneration tower. A flow meter, a pressure transmitter, a flow regulating valve, a check valve, and a manual stop valve are also configured.
[0010] The utility model introduces nitrogen and steam into a flash tank. Since other inert gases that do not react are introduced into the flash tank to reduce the partial pressure of CO2, the solubility of the CO2 volatile solute in the alcoholamine rich liquid is proportional to the CO2 equilibrium pressure of the solute on the liquid surface of the alcoholamine rich liquid under isothermal and isobaric conditions. After the partial pressure of CO2 is reduced, the introduction of steam compensates for the heat loss of the introduction of cold nitrogen, and further performs gas-liquid separation. The gaseous substance is flashed by nitrogen and steam to achieve the purpose of removing CO2. BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Figure 1 It is a schematic diagram of the connection structure of the utility model. DETAILED DESCRIPTION
[0012] A device for improving the decarburization effect of hydrogen-rich carbon circulating oxygen blast furnace gas flash tank, such as Figure 1 As shown, it includes an absorption tower 2, a flash tank 3, a regeneration tower 5, a nitrogen system and a steam system. The flash tank 3 is connected to the absorption tower 2. The lower part of the absorption tower 2 is connected to the raw gas inlet pipe 1. The raw gas is hydrogen-rich carbon circulating oxygen blast furnace top gas. The pressure of the raw gas entering the absorption tower is 1.5-1.7Mpa. The nitrogen pipe 6 of the nitrogen system is connected to the purge port of the flash tank 3. The high-pressure nitrogen input to the flash tank is controlled at 0.6-0.8MPa. The nitrogen pipe is DN 150; the steam pipe 7 of the steam system is connected to the purge port of the flash tank 3, the steam pressure is controlled at 0.4-0.6MPa, and the steam pipe is DN400; the outlet of the flash tank is provided with a double-line parallel exhaust pipe 8; the flash tank 3 is connected to the regeneration tower 5 through the bottom rich liquid pipe 4, the nitrogen pipe 6 is connected to the bottom rich liquid pipe 4, the nitrogen lift pressure input by the nitrogen pipe is controlled at 0.6-0.8MPa, and the nitrogen pipe is DN65.
[0013] The alcohol amine solution used in the absorption tower 2 is a 30% by mass methyldiethanolamine aqueous solution, with a 5% by mass activator added, the absorption temperature is 40°C, and the absorption pressure is the same as the intake pressure of the raw gas; the pressure of the flash tank is 300kPa, the temperature of the flash tank is 80°C, the gas nitrogen flow rate is 5000Nm³ / h-12000 Nm³ / h, and the flow rate of the heating steam is 8t / h-15 t / h. The nitrogen pipe 6 of the nitrogen system is equipped with a flow meter, a pressure transmitter, a flow regulating valve, a check valve, and a manual stop valve. The steam pipe 7 is connected to the opening on the pipeline in front of the steam temperature reduction and pressure reducing valve, and the steam pipe 7 is also equipped with a flow meter, a thermocouple, a pressure transmitter, a steam flow regulating valve, a check valve, front and rear manual stop valves, and a steam trap.
Claims
1. A device for improving the decarburization effect of a hydrogen-rich carbon circulating oxygen blast furnace gas flash tank, comprising an absorption tower, a flash tank, a regeneration tower, a nitrogen system and a steam system, characterized in that: The flash tank is connected with the absorption tower, and the lower part of the absorption tower is connected with the raw gas inlet pipe, the raw gas is hydrogen-rich carbon cycle oxygen blast furnace top gas, and the pressure of the raw gas entering the absorption tower is 1.5-1.7Mpa, the nitrogen pipe of the nitrogen system is connected with the purge port of the flash tank, the high-pressure nitrogen input into the flash tank is controlled at 0.6-0.8MPa, and the nitrogen pipe is DN150; the steam pipe of the steam system is connected with the purge port of the flash tank, the steam pressure is controlled at 0.4-0.6MPa, and the steam pipe is DN400; the outlet of the flash tank is provided with a double-line parallel exhaust pipeline; the flash tank is connected with the regeneration tower through the bottom rich liquid pipe, the nitrogen pipe is connected with the bottom rich liquid pipe, the nitrogen gas lift pressure input by the nitrogen pipe is controlled at 0.6-0.8MPa, and the nitrogen pipe is DN65.