Dynamic water balance control system of ship carbon capture system

Abstract

The invention provides a dynamic water balance control system for a ship carbon capture system. The dynamic water balance control system comprises an absorption tower, a desorption tower, a cooling separation unit and a liquid storage unit. A spraying device of the absorption tower is used for reversely contacting the organic amine solution with the flue gas so as to capture carbon dioxide and generate an amine-rich solution. Heating and regenerating the amine-rich solution in the desorption tower to obtain a lean amine solution and a mixed gas, and returning the lean amine solution to the absorption tower from a liquid phase outlet for recycling. The cooling and separating unit comprises a cooling device and a separating device, the cooling device is used for cooling the mixed gas discharged from the desorption tower, and the separating device is used for separating the mixed gas cooled by the cooling device. The liquid storage unit is used for collecting liquid amine-containing water and enabling the liquid amine-containing water to flow back to the spraying device. According to the scheme, dynamic water balance and efficient amine liquid recovery of the system are achieved, water vapor and entrained organic amine are recovered through the cooling separation unit, water and the amine liquid are collected in a centralized mode through the liquid storage unit, and continuous loss of the amine liquid is avoided while the stability of the total water amount in the system is maintained.

Description

Technical Field

[0001] This application relates to the field of ship carbon emission reduction technology, and more specifically to a dynamic water balance control system for a ship carbon capture system. Background Technology

[0002] The shipping industry can achieve its emission reduction targets through ship carbon capture technology. Among the many carbon capture technologies, chemical absorption has advantages such as high capture efficiency, high technological maturity, significant cost-effectiveness, and compact equipment.

[0003] In chemical absorption, the organic amine solution needs to be heated to desorb the absorbed carbon dioxide. This process results in the evaporation of a large amount of liquid water, which also carries away some of the organic amine solution. Furthermore, the propulsion from ship exhaust gases can cause some organic amine solution to escape from the top of the absorption tower into the atmosphere. These two factors accelerate the loss of organic amine solution and liquid water in the ship's carbon capture system, leading to accelerated system degradation, reduced processing capacity, and increased operating costs. The escape of chemicals can also cause secondary pollution problems.

[0004] Therefore, there is a need to provide a dynamic water balance control system for ship carbon capture systems to at least partially solve the above problems. Summary of the Invention

[0005] The summary section introduces a series of simplified concepts, which will be further explained in detail in the detailed description section. This summary section is not intended to limit the key and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0006] To at least partially solve the above problems, this application provides a dynamic water balance control system for a ship carbon capture system, used in the ship carbon capture process, comprising: The absorption tower has a flue gas inlet at the bottom and a spray device at the top. The spray device is used to counter-currently contact the organic amine solution with the flue gas to capture carbon dioxide and generate a rich amine solution. The desorption tower has a liquid phase inlet that is fluidly connected to the liquid phase outlet of the absorption tower, and a liquid phase outlet that is fluidly connected to the spray device. It is used to heat and regenerate the rich amine solution in the desorption tower to obtain a lean amine solution and a mixed gas. The lean amine solution is returned to the absorption tower from the liquid phase outlet for recycling. The cooling and separation unit is in fluid communication with the gas phase outlet of the desorption tower. The cooling and separation unit includes a cooling device and a separation device. The cooling device is used to cool the mixed gas discharged from the desorption tower, and the separation device is used to separate the mixed gas cooled by the cooling device to obtain liquid amine-containing water and gaseous carbon dioxide. The liquid storage unit is in fluid communication with the liquid phase outlet of the separation device and is used to collect the liquid amine-containing water and return it to the spraying device.

[0007] The dynamic water balance control system for the ship carbon capture system disclosed in this application achieves dynamic water balance and efficient amine recovery, ensuring stable system operation. By employing a cooling separation unit to cool and separate the high-temperature mixed gas discharged from the desorption tower, water vapor and entrained organic amines can be efficiently recovered and converted into liquid amine-containing water. Simultaneously, by setting up a liquid storage unit, water and amine lost from the desorption tower can be collected and reinjected into the absorption tower according to preset operating conditions. This effectively prevents continuous amine loss and controls amine concentration fluctuations while maintaining a stable total water volume within the system, fundamentally solving the problems of efficiency decline and operational instability caused by water balance and amine loss in ship carbon capture systems.

[0008] Optionally, the absorption tower includes a demister for removing organic amine droplets entrained in the flue gas.

[0009] Optionally, the demister is located upstream of the gas phase outlet along the flow direction of the flue gas.

[0010] Optionally, the spraying device includes a nozzle disposed above the defogging device and facing the defogging device to rinse the defogging device.

[0011] Optionally, the system further includes a drying unit, the inlet of which is in fluid communication with the gas phase outlet of the separation device, and the liquid phase outlet of which is in fluid communication with the liquid storage unit.

[0012] Optionally, the drying unit is a cooling dryer or a drying device containing a heat exchanger.

[0013] Optionally, the cooling device is a gas-liquid heat exchanger.

[0014] Optionally, the hot-side channel of the gas-liquid heat exchanger is in fluid communication with the gas phase outlet of the desorption tower, and the cold-side channel is used to connect to cooling water.

[0015] Optionally, the desorption tower is equipped with a heater.

[0016] Optionally, the system further includes a condensate pump, the inlet of which is in fluid communication with the liquid storage unit and the outlet of which is in fluid communication with the spraying device, for pressurizing and conveying the liquid amine-containing water to the absorption tower. Attached Figure Description

[0017] The following drawings, illustrating embodiments of this application, are incorporated herein by reference and are used to understand this application. The drawings illustrate embodiments of this application and their descriptions, serving to explain the principles of this application. In the drawings, Figure 1 This is a schematic diagram of a dynamic water balance control system for a ship carbon capture system according to a preferred embodiment of this application.

[0018] Explanation of reference numerals in the attached figures 1: Absorption Tower 2: Desorption Tower 3: Cooling device 4: Drying unit 5: Separation device 6: Liquid Storage Unit 7: Condensate pump 8: Defogging device 9: Spraying device 10: Heater Detailed Implementation

[0019] In the following description, numerous specific details are set forth to provide a more thorough understanding of this application. However, it will be apparent to those skilled in the art that embodiments of this application may be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described to avoid confusion with embodiments of this application.

[0020] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms “comprising” and / or “including” are used in this specification, they indicate the presence of the stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or combinations thereof.

[0021] In this document, ordinal numbers such as “first” and “second” used in this application are merely identifiers and do not have any other meaning, such as a specific order. Moreover, for example, the term “first component” does not imply the existence of a “second component”, and the term “second component” does not imply the existence of a “first component”.

[0022] In this article, terms such as "up," "down," "front," "back," "left," and "right" are used only to indicate the relative positional relationship between related parts, rather than to define the absolute position of these related parts.

[0023] In this document, terms such as “equal” and “same” are not strict mathematical and / or geometric limitations, but also include errors that are understandable to those skilled in the art and permissible in manufacturing or use.

[0024] Unless otherwise stated, the numerical ranges in this document include not only the entire range within its two endpoints, but also the subranges contained therein.

[0025] Exemplary embodiments according to this application will now be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. It should be understood that these embodiments are provided so that the disclosure of this application is thorough and complete, and that the concept of these exemplary embodiments is fully conveyed to those skilled in the art.

[0026] Reference Figure 1 This application provides a dynamic water balance control system for a ship carbon capture system, used in the ship carbon capture process.

[0027] The dynamic water balance control system of the ship carbon capture system includes an absorption tower 1, a desorption tower 2, a cooling separation unit, and a liquid storage unit 6.

[0028] The absorption tower 1 has a flue gas inlet at its bottom, through which the flue gas emitted by the ship's engine enters. A spray device 9 is installed at the top of the absorption tower 1. This spray device atomizes the organic amine solution, allowing it to come into counter-current contact with the rising flue gas. During this counter-current contact, the organic amine solution selectively absorbs carbon dioxide from the flue gas, achieving carbon capture. The amine-rich solution is then discharged from the liquid phase outlet at the bottom of the tower, and clean flue gas is discharged from the gas phase outlet at the top of the tower, thus achieving carbon emission reduction.

[0029] The function of desorption tower 2 is to provide a high-temperature, low-pressure environment for the amine-rich solution, allowing carbon dioxide to be released and regenerating the organic amine solution. The liquid phase inlet of desorption tower 2 is fluidly connected to the liquid phase outlet of absorption tower 1, and the amine-rich solution is transported to desorption tower 2. The liquid phase outlet of desorption tower 2 is fluidly connected to spray device 9. The amine-rich solution is heated and regenerated within desorption tower 2, and the regenerated lean amine solution is returned to absorption tower 1 from the liquid phase outlet for recycling. The released carbon dioxide and a large amount of water vapor form a mixed gas. This mixed gas carries organic amine droplets and is discharged from the top of desorption tower 2.

[0030] During the desorption process in desorption tower 2, a large amount of liquid water is evaporated, and some organic amine solution is also carried away. To reduce the loss of organic amine solution and liquid water, this scheme uses a cooling separation unit to recover organic amine and liquid water.

[0031] The cooling separation unit is in fluid communication with the gas phase outlet of the desorption tower 2. The cooling separation unit includes a cooling device 3 and a separation device 5. The cooling device 3 is used to cool the mixed gas containing carbon dioxide and water vapor discharged from the desorption tower 2, and the separation device 5 is used to separate the mixed gas cooled by the cooling device 3 to obtain liquid amine-containing water and gaseous carbon dioxide.

[0032] The liquid storage unit 6 is in fluid communication with the liquid phase outlet of the separation device 5. Optionally, the liquid storage unit 6 is constructed as an atmospheric or low-pressure storage tank with a level gauge, and its inlet is in fluid communication with the liquid phase outlet of the separation device 5, for collecting the separated liquid amine-containing water.

[0033] This solution achieves dynamic water balance and efficient amine recovery, ensuring stable system operation. By employing a cooling and separation unit to cool and separate the high-temperature mixed gas discharged from desorption tower 2, water vapor and entrained organic amines can be efficiently recovered and converted into liquid amine-containing water. Simultaneously, the liquid storage unit 6 ensures that water and amine lost from desorption tower 2 are collected and reinjected into absorption tower 1 according to preset operating conditions. This maintains a stable total water volume within the system while effectively preventing continuous amine loss and controlling amine concentration fluctuations, fundamentally solving the problems of reduced efficiency and unstable operation in ship carbon capture systems caused by water balance and amine loss.

[0034] Optionally, the absorption tower 1 includes a demister 8 for removing organic amine droplets entrained in the flue gas. The organic amine droplets in the flue gas will collide with the surface of the demister 8 and form a liquid film, thereby significantly reducing the amount of organic amine droplets carried by the flue gas and preventing their escape.

[0035] Based on the above embodiment, the demister 8 is located upstream of the gas phase outlet along the flue gas flow direction. Before the flue gas is discharged from the system, it must pass through the demister 8, where entrained organic amine droplets are effectively captured, achieving primary control of amine escape.

[0036] Optionally, the spray device 9 includes multiple nozzles. In some embodiments, the nozzles are positioned above the demister 8, and their spray direction is adjusted to be directly towards the demister 8; specifically, the spray direction of the nozzles is vertical or inclined downwards. This allows the liquid amine-containing water sprayed through the nozzles to not only absorb carbon dioxide but also to rinse the demister 8. The rinsing water washes away the amine liquid accumulated on the demister 8, preventing amine droplets from clogging the mesh of the demister 8, and allowing the amine liquid to re-enter the liquid circulation of the absorption tower 1. This cleans the demister 8, maintaining its efficient operation, and also recovers the amine liquid. The arrangement of the nozzles and the demister 8 not only achieves water balance control but also enables amine escape treatment.

[0037] In this scheme, the system also includes a drying unit 4, which processes the carbon dioxide and liquid amine-containing water to obtain dried carbon dioxide and liquid amine-containing water. The inlet of the drying unit 4 is in fluid communication with the gas phase outlet of the separation device 5, and the liquid phase outlet of the drying unit 4 is in fluid communication with the storage unit 6. The liquid phase outlet also returns the trace amount of amine-containing water generated by deep condensation to the storage unit 6. In some embodiments, the drying unit 4 is a cooling dryer or a drying device including a heat exchanger. After the wet carbon dioxide gas enters, it is deeply cooled to a lower temperature, causing the residual water vapor to condense further.

[0038] This solution significantly reduces the dew point and water content of carbon dioxide gas through secondary cooling and separation by separation device 5 and drying unit 4.

[0039] Based on the above embodiments, the storage tank of the liquid storage unit 6 is equipped with at least two inlets: a main inlet connected to the liquid phase outlet of the cooling separation unit, and an auxiliary inlet connected to the liquid phase outlet of the drying unit 4. This multi-channel converging structure ensures that the liquid water recovered from all stages of the system can be collected and managed uniformly, providing a centralized reservoir for water balance control.

[0040] Optionally, the cooling device 3 is a gas-liquid heat exchanger. In some embodiments, the hot-side channel of the gas-liquid heat exchanger is in fluid communication with the gas phase outlet of the desorption tower 2, and the cold-side channel is used to connect cooling water, which acts as a refrigerant to remove heat. In the cooling device 3, most of the water vapor undergoes a phase change and condenses into liquid water. In the subsequent separation device 5, the condensed liquid amine-containing water is initially separated from the cooled carbon dioxide gas.

[0041] Optionally, a heater 10 is provided inside the desorption tower 2. Optionally, the heater 10 is located in the lower half of the desorption tower 2, and the solubility of carbon dioxide decreases by heating, so that it is released in the packing or trays inside the desorption tower 2.

[0042] Optionally, the system also includes a condensate pump 7, whose inlet is connected to the storage unit 6 via a pipeline, and whose outlet is in fluid communication with the spray device 9, for pressurizing and conveying liquid amine-containing water to the absorption tower 1. The condensate pump 7 provides the power required to convey the recycled water from the low-pressure storage tank to the high-level absorption tower 1. By controlling the pump's head and flow rate, the return water volume can be precisely adjusted, thereby achieving dynamic water balance in the system.

[0043] The system operates as follows: Ship exhaust gas enters from the bottom of absorption tower 1 and comes into countercurrent contact with the amine liquid sprayed from the top, where carbon dioxide is absorbed. The purified exhaust gas is then discharged after amine droplets are removed by the demister 8. The amine-rich liquid is sent to desorption tower 2, where it is heated by heater 10 to release carbon dioxide and water vapor. The high-temperature mixed gas enters the cooling and separation unit, where it is cooled and condensed, separating liquid amine-containing water and moist carbon dioxide. The liquid amine-containing water is stored in storage unit 6. The moist carbon dioxide enters the drying unit 4, where it is further dried before being discharged, yielding a high-purity carbon dioxide product. Simultaneously, drying unit 4 collects the amine liquid and sends it to storage unit 6. The liquid amine-containing water in storage unit 6 is pumped back to absorption tower 1 by condensate pump 7. The entire system achieves closed-loop management of water and amine, ensuring stability, high efficiency, and environmental friendliness.

[0044] To clearly and objectively demonstrate the beneficial effects of the technical solution of this application in maintaining water balance and controlling amine escape, this solution provides the following one embodiment and three comparative examples.

[0045] Example 1 The system comprises an absorption tower 1, a desorption tower 2, a cooling separation unit, a drying unit 4, a liquid storage unit 6, a condensate pump 7, and connecting pipelines. The absorption tower 1 is equipped with a demister 8 at its top, with a flushing nozzle spraying towards it from above. The liquid storage unit 6, via the condensate pump 7 and a return pipeline, transports the collected amine-containing liquid to the spray device 9 and flushing nozzles at the top of the absorption tower 1. The desorption tower 2 contains a heater 10, and the drying unit 4 is a cooling dryer. All components are connected via pipelines to form a closed-loop system with complete condensate return and active amine escape recovery: the liquid phase outlet of the absorption tower 1 is connected to the liquid phase inlet of the desorption tower 2; the gas phase outlet of the desorption tower 2 is connected to the inlet of the cooling separation unit; the liquid phase outlet of the cooling separation unit is connected to the liquid storage unit 6; the outlet of the liquid storage unit 6 is connected to the top of the absorption tower 1 via the condensate pump 7; the inlet of the drying unit 4 is connected to the gas phase outlet of the cooling separation unit, and the liquid phase outlet is connected to the liquid storage unit 6.

[0046] This embodiment solves both the water balance and amine escape problems through condensate recirculation and rinsing with the demister 8. Through actual operation testing, this embodiment achieved the following results: During the heating and regeneration process in desorption tower 2, approximately 0.5 to 1.5 tons of water vapor are generated for every 1 ton of CO2 released (the exact amount depends on the operating pressure inside the tower). This system, through closed-loop recovery, can almost completely recover this evaporated water, thereby controlling the concentration fluctuation of the circulating amine solution within a very small range and significantly reducing the need for external freshwater replenishment.

[0047] The concentration of amine droplets in the flue gas at the outlet of absorber tower 1 was tested, and this system can stably reduce it to 50 mg / Nm³. 3Below, the amine solute slip is approximately 1~2 kg / t CO2. This is compared to a control system without a demister (outlet concentration typically 100~200 mg / Nm³). 3 ), the amine escape rate decreased by 70% to 80%.

[0048] The demister 8 is flushed every 30 minutes to 1 hour during operation. The efficiency of the demister 8 is restored and maintained above 99%, and the outlet droplet concentration is stabilized at 50 mg / Nm³. 3 the following.

[0049] Comparative Example 1: Carbon capture system without condensate recirculation Comparative Example 1 has a similar configuration to Example 1, except that the return pipeline connecting the liquid storage unit 6 to the absorption tower 1 and the condensate pump 7 are removed; the liquid water separated from the cooling separation unit and the drying unit 4 is collected and discharged as wastewater, while an equal amount of external fresh water needs to be continuously added to the absorption tower 1 to maintain the liquid level.

[0050] In the comparative example, a large amount of water vapor (approximately 0.5~1.5 t water / t CO2) evaporated during desorption was permanently lost, causing a continuous increase in the concentration of circulating amine solution within the system, making stable operation impossible. The decrease in organic amine solution concentration necessitates the addition of additional amine solution, preventing the system from operating stably for extended periods.

[0051] Comparative Example 2: Carbon capture system without demister and flushing function Comparative Example 2 has a similar configuration to Example 1, but the demister 8 and related flushing nozzles in the absorption tower 1 are completely removed; after being sprayed and washed in the absorption tower 1, the flue gas is discharged directly from the gas phase outlet without any demister 8.

[0052] In this comparative example, the outlet amine droplet concentration of the system is typically as high as 100–200 mg / Nm³. 3 The amount of amine solute escaped was much higher than in Example 1, resulting in significant amine liquid loss and environmental pollution risks.

[0053] Comparative Example 3: A carbon capture system with a demister 8 but without a flushing function Comparative Example 3 has a configuration similar to Example 1, with a demister 8 installed inside the absorption tower 1, but no flushing nozzles are provided facing the demister 8.

[0054] In this comparative example, the demister 8 was effective in the initial stage of operation, but its efficiency gradually decreased as the amine liquid accumulated on the surface of the demister 8. For example, for the baffle demister, after 30 minutes to 1 hour of operation, its demister efficiency dropped from over 99% to about 90%, and the outlet amine droplet concentration rose back to over 100 mg / Nm³. 3 It is impossible to achieve long-term stable control of amine escape.

[0055] Unless otherwise defined, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for descriptive purposes only and is not intended to limit the scope of this application. Terms such as “setup” appearing herein can refer to either a component being directly attached to another component or a component being attached to another component via an intermediary. A feature described in one embodiment herein may be applied, alone or in combination with other features, to another embodiment, unless that feature is not applicable in that other embodiment or is otherwise stated.

[0056] This application has been described through the above embodiments; however, it should be understood that the above embodiments are for illustrative purposes only and are not intended to limit this application to the described embodiments. Those skilled in the art will understand that many more variations and modifications can be made based on the teachings of this application, and all such variations and modifications fall within the scope of protection claimed in this application.

Claims

1. A dynamic water balance control system for a ship carbon capture system, used in the ship carbon capture process, characterized in that, include: The absorption tower has a flue gas inlet at the bottom and a spray device at the top. The spray device is used to counter-currently contact the organic amine solution with the flue gas to capture carbon dioxide and generate a rich amine solution. The desorption tower has a liquid phase inlet that is fluidly connected to the liquid phase outlet of the absorption tower, and a liquid phase outlet that is fluidly connected to the spray device. It is used to heat and regenerate the rich amine solution in the desorption tower to obtain a lean amine solution and a mixed gas. The lean amine solution is returned to the absorption tower from the liquid phase outlet of the desorption tower for recycling. The cooling and separation unit is in fluid communication with the gas phase outlet of the desorption tower. The cooling and separation unit includes a cooling device and a separation device. The cooling device is used to cool the mixed gas discharged from the desorption tower, and the separation device is used to separate the mixed gas cooled by the cooling device to obtain liquid amine-containing water and gaseous carbon dioxide. The liquid storage unit is in fluid communication with the liquid phase outlet of the separation device and is used to collect the liquid amine-containing water and return it to the spraying device.

2. The dynamic water balance control system for a ship carbon capture system according to claim 1, characterized in that, The absorption tower includes a demister for removing organic amine droplets entrained in the flue gas.

3. The dynamic water balance control system for a ship carbon capture system according to claim 2, characterized in that, Along the flow direction of the flue gas, the demister is located upstream of the gas phase outlet.

4. The dynamic water balance control system for a ship carbon capture system according to claim 2 or 3, characterized in that, The spraying device includes a nozzle, which is positioned above the defogging device and faces the defogging device to rinse the defogging device.

5. The dynamic water balance control system for a ship carbon capture system according to claim 1, characterized in that, The system further includes a drying unit, the inlet of which is in fluid communication with the gas phase outlet of the separation device, and the liquid phase outlet of which is in fluid communication with the liquid storage unit.

6. The dynamic water balance control system for a ship carbon capture system according to claim 5, characterized in that, The drying unit is a cooling dryer or a drying device that includes a heat exchanger.

7. The dynamic water balance control system for a ship carbon capture system according to claim 1, characterized in that, The cooling device is a gas-liquid heat exchanger.

8. The dynamic water balance control system for a ship carbon capture system according to claim 7, characterized in that, The hot-side channel of the gas-liquid heat exchanger is in fluid communication with the gas phase outlet of the desorption tower, and the cold-side channel is used to connect to cooling water.

9. The dynamic water balance control system for a ship carbon capture system according to claim 1, characterized in that, The desorption tower is equipped with a heater.

10. The dynamic water balance control system for a ship carbon capture system according to claim 1, characterized in that, The system also includes a condensate pump, the inlet of which is in fluid communication with the liquid storage unit and the outlet of which is in fluid communication with the spraying device, for pressurizing and transporting the liquid amine-containing water to the absorption tower.

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