Heating regeneration and vacuum regeneration coupled low-energy-consumption amine liquid decarbonization system

Abstract

The utility model discloses a heating regeneration and vacuum regeneration coupled low-energy-consumption amine liquid decarbonization system, and belongs to the technical field of energy conservation and environmental protection. The utility model solves the problem of high energy consumption caused by the fact that the heated and regenerated lean amine solution needs to be cooled through a cooling tower before entering an absorption tower in order to ensure that the lean amine solution has high absorption capacity in the absorption tower in the conventional decarbonization system. An amine liquid outlet at the bottom of the regeneration tower is connected to an inlet of the flash evaporator, and a lean amine liquid outlet of the flash evaporator is connected to a lean amine liquid inlet of the absorption tower. The flash evaporation process is arranged between the regeneration tower and the absorption tower, the solubility characteristic of carbon dioxide in the amine liquid is utilized, high vacuum is applied to achieve further mass decarburization, in the vacuum decarburization process, the temperature of the amine liquid can be further reduced, and then energy consumption is effectively reduced.

Description

Technical Field

[0001] This utility model relates to a low-energy-consumption amine liquid decarbonization system that couples heating regeneration with vacuum regeneration, belonging to the field of energy-saving and environmental protection technology. Background Technology

[0002] Traditional decarbonization systems employ heating regeneration, primarily utilizing amine solution (MEDA) as the absorbent and steam as the heat source for regenerating the rich amine solution. This method has relatively high overall energy consumption, requiring a large amount of high-quality steam as the power source for the regeneration of the rich amine solution. However, heating regeneration leads to a high temperature level in the lean amine solution, necessitating cooling through cooling towers or similar means before it enters the absorption tower to ensure sufficient absorption capacity within the tower. Conventional technical routes consume large quantities of high-quality steam, resulting in significant energy consumption. Utility Model Content

[0003] This invention addresses the problem in existing conventional decarbonization systems where, in order to ensure that the lean amine solution has a high absorption capacity in the absorption tower, it needs to be cooled in a cooling tower before entering the absorption tower after heating and regeneration, which leads to high energy consumption. Therefore, this invention provides a low-energy-consumption amine solution decarbonization system that couples heating and regeneration with vacuum regeneration.

[0004] The technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows:

[0005] A low-energy amine decarbonization system coupling heating regeneration and vacuum regeneration includes a regeneration tower and a flash evaporator. The bottom amine outlet of the regeneration tower is connected to the amine inlet of the flash evaporator, and the amine outlet of the flash evaporator is connected to the lean amine inlet of the absorption tower.

[0006] Furthermore, a venting tower is connected to the carbon dioxide outlet of the regeneration tower.

[0007] Furthermore, a flash tank is connected between the amine-rich liquid outlet of the absorption tower and the first amine liquid inlet of the regeneration tower.

[0008] Furthermore, the gas outlet of the flash tank is connected to the venting tower.

[0009] Furthermore, the flash vapor outlet of the flash evaporator is connected to a condenser, the gas outlet of the condenser is connected to a vacuum pump, and the outlet of the vacuum pump is connected to a venting tower.

[0010] Furthermore, the condenser is a spray tower, the flash steam outlet of the flash evaporator is connected to the water vapor inlet of the spray tower, the spray tower is connected to a cooling water inlet and a cooling water outlet, the sprayer inside the spray tower is connected to the cooling water inlet, and the top of the spray tower is connected to a water vapor outlet.

[0011] Furthermore, the condenser is a partitioned condenser, and a cooling tower is connected to the heat absorption side of the condenser.

[0012] Furthermore, the condensate outlet of the condenser is connected to the lean amine inlet of the absorption tower via a condensate pump.

[0013] Furthermore, a lean liquid circulation pump set is installed between the amine liquid outlet of the flash evaporator and the lean amine liquid inlet of the absorption tower.

[0014] Furthermore, a circulation pipeline is connected between the bottom of the regeneration tower and the lower part of the regeneration tower, and a lean liquid filtration pump and a filter are installed on the circulation pipeline.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] This invention relates to a low-energy-consumption amine decarbonization system that couples heating regeneration with vacuum regeneration. The flash evaporation process is placed between the regeneration tower and the absorption tower. After the rich amine liquid is regenerated in the regeneration tower, the solubility of carbon dioxide in the amine liquid is utilized. Under low temperature and low pressure conditions, the ambient pressure of the amine liquid drops rapidly, and its carbon dioxide solubility decreases rapidly. At this time, high vacuum is used to achieve further large-scale decarbonization. Furthermore, due to the principle of heat absorption during liquid evaporation, the temperature of the amine liquid is further reduced during the vacuum decarbonization process, thereby effectively reducing energy consumption. Attached Figure Description

[0017] Fig. 1 This is a schematic diagram of the structural composition of a low-energy-consumption amine decarbonization system that couples heating regeneration and vacuum regeneration when the condenser is a spray tower.

[0018] Fig. 2 This is a schematic diagram of the structural composition of a low-energy-consumption amine decarbonization system coupled with heating regeneration and vacuum regeneration, when the condenser is a wall-mounted condenser.

[0019] Fig. 3 This is a schematic diagram of the structure of the flash evaporator and condenser when the condenser uses a spray tower.

[0020] In the picture:

[0021] 1. Absorber; 1-1. Lean amine solution outlet; 1-2. Lean amine solution inlet; 2. Regeneration tower; 2-1. First amine solution inlet; 2-2. Second amine solution inlet; 2-3. First amine solution outlet; 2-4. Bottom amine solution outlet; 3. Reboiler; 4. Flash evaporator; 5. Flash tank; 6. Venting tower; 7. Condenser; 7-1. Cooling water inlet; 7-2. Cooling water outlet; 7-3. Steam outlet; 8. Vacuum pump; 9. Condensate pump; 10. Lean amine solution circulation pump set; 11. Cooling tower; 12. Lean amine solution filter pump; 13. Filter. Detailed Implementation

[0022] Specific implementation method one: Combining Figs. 1-3 This description aims to clearly and completely describe the technical solutions in this utility model. Obviously, the described embodiments are only a part of the embodiments of this utility model, not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0023] It should be noted that the descriptions of "front," "rear," "left," "right," "inner," "outer," "left side," "right side," "upper part," "lower part," "top," and "bottom" in this utility model are defined based on the orientation or positional relationships shown in the accompanying drawings. They are merely for the convenience of describing this utility model and for simplifying the description, and do not indicate or imply that the described structure must be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In the description of this utility model, "multiple" means two or more, unless otherwise explicitly specified.

[0024] In the description of this utility model, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0025] A low-energy amine decarbonization system coupled with heating regeneration and vacuum regeneration includes a regeneration tower 2 and a flash evaporator 4. The bottom amine outlet 2-4 of the regeneration tower 2 is connected to the amine inlet of the flash evaporator 4, and the amine outlet of the flash evaporator 4 is connected to the lean amine inlet 1-2 of the absorption tower 1.

[0026] The absorption tower 1 and the regeneration tower 2 are both components of an existing heating and regeneration decarbonization system. The rich amine liquid outlet 1-1 of the absorption tower 1 is connected to the first amine liquid inlet 2-1 of the regeneration tower 2. The first amine liquid outlet 2-3 and the second amine liquid inlet 2-2 of the regeneration tower 2 are respectively connected to the heat absorption side of the reboiler 3 through pipelines. The reboiler 3 can be a heat exchanger with high-temperature steam as a heat source, or any heating device that can heat the medium in the regeneration tower 2 to make it boil and remove carbon.

[0027] The semi-lean amine liquid discharged from regeneration tower 2 enters flash evaporator 4 to achieve vacuum regeneration of semi-lean amine liquid in the low-temperature section, effectively reducing the overall system energy consumption and expanding the system's decarbonization capacity. In other words, through the low-energy amine liquid decarbonization system of this invention, which couples heating regeneration with vacuum regeneration, the decarbonization cycle of amine liquid can be completed with low energy consumption, reducing steam consumption.

[0028] This invention relates to a low-energy-consumption amine decarbonization system that couples heating regeneration with vacuum regeneration. Based on existing conventional heating regeneration decarbonization systems, the flash evaporation process is placed between regeneration tower 2 and absorption tower 1. After the rich amine liquid is regenerated through regeneration tower 2, the solubility of carbon dioxide in the amine liquid is utilized. Under low temperature and low pressure conditions, the ambient pressure of the amine liquid drops rapidly, and its carbon dioxide solubility decreases rapidly. At this time, high vacuum is used to achieve further large-scale decarbonization. Furthermore, due to the principle of heat absorption during liquid evaporation, the temperature of the amine liquid is further reduced during the vacuum decarbonization process, thereby effectively reducing energy consumption.

[0029] A flash tank 5 is installed between the amine-rich liquid outlet 1-1 of the absorption tower 1 and the first amine liquid inlet 2-1 of the regeneration tower 2. This design allows for initial expansion and cooling before the regeneration tower 2, resulting in the discharge of small amounts of carbon dioxide and water vapor. The flash pressure range of the flash tank 5 is 30–50 kPa·a, and the flash pressure range of the flash evaporator 4 is 1.7–4.2 kPa·a.

[0030] The carbon dioxide outlet of regeneration tower 2 is connected to a venting tower 6. This design allows the gas released from regeneration tower 2 to be discharged and treated through the venting tower 6.

[0031] The gas outlet of flash tank 5 is connected to venting tower 6. This design allows for the venting tower 6 to discharge and treat the gas released from flash tank 5.

[0032] The flash vapor outlet of flash evaporator 4 is connected to condenser 7, and the gas outlet of condenser 7 is connected to vacuum pump 8. With this design, the flash vapor enters the exothermic side of condenser 7. After the semi-lean amine liquid discharged from regeneration tower 2 enters flash evaporator 4, a large amount of carbon dioxide and water vapor are flashed out in a negative pressure environment. The mixture of carbon dioxide and water vapor is then condensed and reduced in volume by condenser 7, and the carbon dioxide gas is discharged through vacuum pump 8.

[0033] The outlet of vacuum pump 8 is connected to venting tower 6. This design allows the gas released from flash evaporator 4 to be discharged and treated through venting tower 6.

[0034] The condenser can be a spray condenser or a partition condenser.

[0035] When the condenser is a spray tower, the flash steam outlet of the flash evaporator 4 is connected to the water vapor inlet of the spray tower. The spray tower is equipped with a cooling water inlet 7-1 and a cooling water outlet 7-2, and the sprayers inside the spray tower are connected to the cooling water inlet 7-1. The top of the spray tower is equipped with a water vapor outlet 7-3. By setting up a spray tower, direct contact heat exchange is achieved.

[0036] The flash evaporator is a single-effect flash evaporator or a multi-effect flash evaporator. When it is a multi-effect flash evaporator, it includes a first-effect flash evaporator to an Nth-effect flash evaporator, where N≥2. Each pair of adjacent flash evaporators is connected through a flash liquid channel. The high-temperature steam outlet of each flash evaporator is connected to a corresponding spray tower, or the high-temperature steam outlet of the multi-effect flash evaporator is connected to a spray tower.

[0037] The spray tower can be a single-stage spray tower or a multi-stage spray tower. When it is a multi-stage spray tower, it includes a first-stage spray tower to an Nth-stage spray tower, where N≥2. The steam inlet is connected to the first-stage spray tower. Each spray tower is equipped with a sprayer, and each spray tower is equipped with a cooling water inlet and a cooling water outlet. A steam channel is connected between each pair of adjacent spray towers.

[0038] When a multi-stage spray tower is used, the cooling water temperature entering the second to Nth stage spray towers is lower than the cooling water temperature entering the first stage spray tower.

[0039] The temperature range of the cooling water entering the first-stage spray tower is 30–50℃, and the temperature range of the cooling water entering the second to Nth-stage spray towers is 8–15℃.

[0040] When the condenser 7 is a partition wall condenser, a cooling tower 11 is connected to the heat absorption side of the condenser 7. This design allows for the condensation and reduction of the mixed gas of carbon dioxide and water vapor flashing out in the condenser 7 via the cooling tower 11. The condensate outlet of the condenser 7 is connected to the lean amine liquid inlet 1-2 of the absorption tower 1 via a condensate pump 9. This design allows the condensate produced by the condenser 7 to enter the absorption tower 1, further cooling the lean amine liquid.

[0041] A lean amine circulation pump group 10 is installed between the amine outlet of flash evaporator 4 and the lean amine inlet 1-2 of absorber 1, and condensate pump 9 is connected to the lean amine circulation pump group 10. This design allows the lean amine liquid, cooled by flash evaporation, to be returned to absorber 1 via the lean amine circulation pump group 10. Simultaneously, the flash condensate discharged from condensate pump 9 can be mixed with the lean amine liquid and returned to absorber 1 via the lean amine circulation pump group 10, ensuring a uniform mixture of the lean amine liquid and flash condensate.

[0042] A circulation pipeline is provided between the bottom of the regeneration tower 2 and the lower part of the regeneration tower 2, and a lean liquid filtration pump 12 and a filter 13 are provided on the circulation pipeline.

[0043] Working principle:

[0044] 1. Rich Amine Liquid System Flow: The low-temperature lean amine liquid absorbs carbon dioxide from the raw blast furnace gas in the absorption tower 1, purifying the raw blast furnace gas. After that, it enters the flash tank 5 for the first expansion and cooling. After discharging a small amount of carbon dioxide and water vapor, it enters the regeneration tower 2. The amine liquid in the upper part of the regeneration tower 2 flows into the reboiler 3. Using high-temperature steam as a heat source, the rich amine liquid is heated and regenerated. After releasing carbon dioxide, the semi-lean amine liquid is discharged.

[0045] 2. Lean Amine Solution System Flow: The semi-lean amine solution discharged from regeneration tower 2 enters flash evaporator 4, where a large amount of carbon dioxide and water vapor are flashed out under negative pressure. This mixed gas is then condensed and reduced in volume by water vapor in condenser 7, and discharged to venting tower 6 by vacuum pump 8. The lean amine solution, cooled by flash evaporation, is pumped back to absorption tower 1 by amine solution pump group. This process of absorption and regeneration is repeated.

[0046] 2. Steam process: High-temperature steam enters reboiler 3, heats the amine liquid that needs to be regenerated, and then generates steam condensate which is discharged from the system.

[0047] 3. Blast furnace gas system process: Blast furnace gas enters absorption tower 1, where it is purified by removing carbon dioxide through lean amine liquid before being discharged.

[0048] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A low-energy-consumption amine liquid decarbonization system coupling heating regeneration and vacuum regeneration, characterized in that: It includes a regeneration tower (2) and a flash evaporator (4). The bottom amine liquid outlet (2-4) of the regeneration tower (2) is connected to the amine liquid inlet of the flash evaporator (4), and the amine liquid outlet of the flash evaporator (4) is connected to the lean amine liquid inlet (1-2) of the absorption tower (1).

2. The low-energy-consumption amine liquid decarbonization system coupled with heating regeneration and vacuum regeneration according to claim 1, characterized in that: The carbon dioxide outlet of the regeneration tower (2) is connected to a venting tower (6).

3. The low-energy-consumption amine liquid decarbonization system coupled with heating regeneration and vacuum regeneration according to claim 2, characterized in that: A flash tank (5) is installed between the amine-rich liquid outlet (1-1) of the absorption tower (1) and the first amine liquid inlet (2-1) of the regeneration tower (2).

4. The low-energy-consumption amine liquid decarbonization system coupled with heating regeneration and vacuum regeneration according to claim 3, characterized in that: The gas outlet of the flash tank (5) is connected to the venting tower (6).

5. The low-energy-consumption amine liquid decarbonization system coupled with heating regeneration and vacuum regeneration according to claim 2, characterized in that: The flash vapor outlet of the flash evaporator (4) is connected to a condenser (7), the gas outlet of the condenser (7) is connected to a vacuum pump (8), and the outlet of the vacuum pump (8) is connected to a venting tower (6).

6. The low-energy-consumption amine liquid decarbonization system coupled with heating regeneration and vacuum regeneration according to claim 5, characterized in that: The condenser is a spray tower. The flash steam outlet of the flash evaporator (4) is connected to the water vapor inlet of the spray tower. The spray tower is connected to a cooling water inlet (7-1) and a cooling water outlet (7-2). The sprayers inside the spray tower are connected to the cooling water inlet (7-1). The top of the spray tower is connected to a water vapor outlet (7-3).

7. The low-energy-consumption amine liquid decarbonization system coupled with heating regeneration and vacuum regeneration according to claim 5, characterized in that: The condenser (7) is a partitioned condenser, and a cooling tower (11) is connected to the heat absorption side of the condenser (7).

8. The low-energy-consumption amine liquid decarbonization system coupled with heating regeneration and vacuum regeneration according to claim 7, characterized in that: The condensate outlet of the condenser (7) is connected to the lean amine inlet (1-2) of the absorption tower (1) via a condensate pump (9).

9. The low-energy-consumption amine liquid decarbonization system coupled with heating regeneration and vacuum regeneration according to claim 1, characterized in that: A lean liquid circulation pump group (10) is installed between the amine liquid outlet of the flash evaporator (4) and the lean amine liquid inlet (1-2) of the absorption tower (1).

10. A low-energy-consumption amine liquid decarbonization system coupled with heating regeneration and vacuum regeneration according to claim 1, characterized in that: A circulation pipeline is provided between the bottom of the regeneration tower (2) and the lower part of the regeneration tower (2), and a lean liquid filter pump (12) and a filter (13) are provided on the circulation pipeline.

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