Carbon dioxide hydrate compression device and storage method based on LNG ship cold energy utilization

Abstract

The application discloses a carbon dioxide hydrate compression device and a storage method based on LNG ship cold energy utilization, and belongs to the technical field of ship transportation and environmental protection.The device comprises a carbon dioxide hydrate generation unit, a carbon dioxide hydrate compression unit, a transportation unit, an LNG cold energy supply and refrigeration unit and a safety and detection unit.The carbon dioxide generated in the ship flue gas is captured by the hydrate method, and is compressed into blocks by a compressor, is loaded into a storage container and is transferred to a refrigeration chamber, wherein the cold energy of the refrigeration chamber is provided by LNG.The application realizes stable and high-density storage by efficiently utilizing the cold energy of the LNG ship, adopting the storage mode of solid carbon dioxide hydrate, improves the carbon capture efficiency of the ship, and can more effectively utilize the transportation resources in long-distance transportation or sea transportation.

Description

Technical Field

[0001] This invention relates to multiple fields such as energy utilization, environmental protection technology, shipping industry and climate change mitigation, and is a new type of carbon dioxide hydrate storage device and method. Background Technology

[0002] The maritime transport industry involves a massive volume of transportation, resulting in high fuel consumption during ship operation. Ships commonly use high-carbon fossil fuels such as heavy oil and marine diesel, which release large amounts of CO2 upon combustion, exacerbating global warming. Ship carbon dioxide harvesting has significant economic value and technological development implications. This invention stems from concerns about carbon emissions in the maritime transport industry and the need for comprehensive energy utilization and environmental protection technologies. Summary of the Invention

[0003] To address the existing carbon dioxide emission problem, this invention provides a carbon dioxide hydrate compression device and storage method based on the utilization of LNG ship cold energy. This invention integrates LNG cold energy, hydrate capture technology, and a novel solid hydrate storage method, aiming to improve energy utilization efficiency and reduce carbon emissions, providing an environmentally friendly and sustainable solution for the shipping industry, and conforming to the global trend of sustainable development.

[0004] The technical solution adopted in this invention is: a carbon dioxide hydrate compression device based on the utilization of cold energy of LNG ships, the device including a carbon dioxide hydrate generation unit, a carbon dioxide hydrate compression unit, a transportation unit, an LNG cold energy supply and refrigeration unit, and a safety and detection unit.

[0005] In the carbon dioxide hydrate generation unit, the reactor is connected to a solid-liquid separator and a hydrate solution recovery tank, respectively.

[0006] The solid-liquid separator is connected to the tank compressor in the carbon dioxide hydrate compression unit via a discharge pipe equipped with a valve.

[0007] The hydrate compression unit incorporates flexible compression materials (such as high-strength elastomers or composite materials) to replace the traditional rigid compression structure. The flexible material can evenly distribute pressure during compression, adapting to the shape changes of the hydrate and preventing damage or performance degradation due to excessive local pressure.

[0008] The outlet of the canister compressor is connected to the inlet of the storage device via a spiral conveyor belt in the transport unit, and the spiral conveyor belt transports the hydrate mold cavity.

[0009] The LNG cold energy supply and refrigeration unit includes a refrigeration chamber and a heat exchanger. The first heat exchanger and the second heat exchanger are located inside the refrigeration chamber, and the first LNG storage tank and the second LNG storage tank are located outside the refrigeration chamber. The first LNG storage tank is connected to the first heat exchanger, and the second heat exchanger is connected to the second LNG storage tank.

[0010] The safety and monitoring unit includes a temperature monitoring system and a pressure monitoring system; the temperature monitoring system installed in the refrigerator compartment is used to ensure that the internal temperature of the refrigerator compartment is maintained within the stable temperature range of the hydrate; the pressure monitoring system installed on the tank compressor is used to adjust the pressure during the compression process according to the morphology of the hydrate.

[0011] A method for storing carbon dioxide hydrate based on the utilization of cold energy from LNG ships, the method comprising the following steps:

[0012] S1. Carbon dioxide in the flue gas is converted into carbon dioxide slurry hydrate in the reactor under high pressure and low temperature. The remaining reaction solution is recycled to the hydrate solution recovery tank. The slurry hydrate is filtered to remove impurities by a solid-liquid separator and then enters the carbon dioxide hydrate compression unit.

[0013] S2. The hydrate slurry is introduced into a tank-shaped compressor by gravity through a discharge port, and compressed into a cake or block shape under high pressure. During the compression process, the hydrate is cooled. A flexible compression material (such as a high-strength elastomer or composite material) is introduced into the hydrate compression unit to replace the traditional rigid compression structure. The flexible material can evenly distribute pressure during compression, adapt to the shape changes of the hydrate, and avoid hydrate damage or performance degradation due to excessive local pressure.

[0014] The compressed carbon dioxide hydrate cakes from S3 are transported from the compression unit to the storage unit inlet via a transport unit. The storage unit is equipped with casters and an automatic docking device at its bottom to ensure alignment with the transport unit. The hydrate cakes are sequentially fed into individual storage compartments, whose sliding doors are automatically opened and closed by an intelligent control system. After loading, the compartments are automatically sealed to maintain a cryogenic environment. This unit utilizes LNG cold energy to provide a continuous cryogenic environment, ensuring long-term stable storage of the hydrates. When unloading or transportation is required, the storage unit unlocks the casters and moves to the target area, achieving automated operation and ensuring efficient and safe storage and transfer processes.

[0015] S4. The compression, transportation, and storage of carbon dioxide hydrate are all carried out in the cold storage room, and the LNG storage tank transfers cold energy to the cold storage room through a heat exchanger.

[0016] Furthermore, a temperature monitoring system installed in the refrigerator compartment is used to ensure that the internal temperature of the refrigerator compartment is maintained within the stable temperature range of the hydrate; a pressure monitoring system installed on the tank compressor is used to adjust the pressure during the compression process according to the morphology of the hydrate.

[0017] Carbon dioxide generated in ship exhaust gas is captured via hydrate extraction. After hydrate formation, the hydrate products are separated, and impurities in the hydrate slurry are removed through a filtration system to obtain a pure hydrate slurry. In the hydrate compression stage, the slurry is introduced into a block compressor, which compresses it into blocks, improving storage and transportation efficiency. The compressed hydrate blocks are loaded into specially designed storage containers, and the containers are transferred from the hydrate formation unit to a refrigerated compartment using a transport unit. The refrigeration of the compartment is provided by LNG. This device and storage method store carbon dioxide hydrate in a solid form, which has a higher storage density and occupies a relatively smaller volume compared to gaseous and liquid states. This helps reduce the space requirements of storage facilities and lower transportation costs, especially in long-distance or maritime transport, allowing for more efficient use of transportation resources. Carbon dioxide hydrate is stable at relatively low temperatures and high pressures, providing a reliable storage method and reducing the risk of carbon dioxide leakage. This high-density storage form of carbon dioxide hydrate... This invention achieves stable and high-density storage by efficiently utilizing the cold energy of LNG ships and employing a solid carbon dioxide hydrate storage method, thereby improving the efficiency of ship carbon capture and providing a solution for the maritime transport industry to achieve more environmentally friendly and sustainable development.

[0018] The beneficial effects of this invention are as follows: The system utilizes the waste heat or cold energy generated by LNG ships to form hydrates through a carbon dioxide hydrate generation unit, and then compresses them into blocks through a hydrate compression unit before transporting them to a cold storage compartment. The cold storage compartment uses the cold energy of LNG to maintain a suitable temperature, achieving stable storage of the hydrates. The entire system ensures safe and stable operation through an automatic control and monitoring system, while also considering waste treatment and energy efficiency, providing an environmentally friendly and efficient technical solution for LNG ship transportation.

[0019] This invention fully utilizes the waste heat or cold energy generated by LNG ships to capture carbon dioxide into hydrates, which are then compressed into blocks for storage and transportation. This innovative technical solution not only achieves efficient utilization and storage of carbon dioxide, but this block-shaped hydrate storage method also features high density and stability. Combined with the transportation characteristics of ships, carbon dioxide can be centrally collected upon arrival at the shore. Furthermore, the environmentally friendly hydrate transportation method reduces greenhouse gas emissions. Simultaneously, utilizing the cold energy of LNG to refrigerate the hydrate blocks not only improves the overall energy utilization efficiency but also provides a sustainable and environmentally friendly solution for the LNG shipping industry. Overall, this invention has multiple beneficial effects, including reducing carbon emissions, improving energy efficiency, complying with environmental regulations, and promoting sustainable development.

[0020] This technology enables efficient and stable compression, cryogenic storage, and safe transportation of carbon dioxide hydrates generated during ship carbon capture, while preventing hydrates from adhering to, clumping, or deteriorating on the inner walls of the equipment. This improves storage efficiency and system reliability, and fully utilizes the cold energy resources generated during LNG ship operation to achieve synergistic benefits of energy recovery and carbon emission reduction. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a carbon dioxide hydrate compression device based on the utilization of cold energy from LNG ships.

[0022] Figure 2 This is a side view of the storage device.

[0023] Figure 3 This is a front view of the storage device.

[0024] In the diagram: 1. Reactor; 2. Hydrate solution recovery tank; 3. First valve; 4. Solid-liquid separator; 5. Second valve; 6. First discharge port valve; 7. Second discharge port valve; 8. Pressure monitoring system; 9. Tank compressor; 10. Hydrate mold cavity; 11. Spiral conveyor belt; 12. Storage device; 13. Temperature monitoring system; 14. First heat exchanger; 15. Second heat exchanger; 16. First LNG storage tank; 17. Second LNG storage tank; 18. Cold storage compartment; 19. Flexible compression plate; 20. Cooling pipe; 21. Pulley; 22. Visual interface; 23. Manual handle; 24. Electric door; 25. Temperature sensor; 26. Pressure sensor. Detailed Implementation

[0025] A carbon dioxide hydrate compression device based on the utilization of cold energy from LNG ships, the device includes a carbon dioxide hydrate generation unit, a carbon dioxide hydrate compression unit, a transportation unit, an LNG cold energy supply and refrigeration unit, and a safety and detection unit.

[0026] In the carbon dioxide hydrate generation unit, reactor 1 is connected to solid-liquid separator 4 and hydrate solution recovery tank 2. Solid-liquid separator 4 is connected to tank compressor 9 in the carbon dioxide hydrate compression unit via a discharge pipe equipped with valves.

[0027] A flexible compression material is introduced into the hydrate compression unit to replace the traditional rigid compression structure. The flexible material can evenly distribute pressure during compression, adapt to the shape changes of the hydrate, and avoid hydrate damage or performance degradation due to excessive local pressure.

[0028] The outlet of the canister compressor 9 is connected to the inlet of the storage device 12 via a spiral conveyor belt 11 in the transport unit. The spiral conveyor belt 11 transports the hydrate mold cavity 10. Each module in the storage device 12 is an independent box-type unit, internally divided into multiple storage compartments, each for storing a single hydrate block. The modular design facilitates loading, unloading, and transportation. A flexible compression plate 19 is installed after each row of storage compartments to ensure the stability of the hydrate cake within the compartments, preventing movement or breakage.

[0029] Each storage module is embedded with a cooling pipe 20, which is connected to the LNG cold energy system. The system maintains a suitable temperature by circulating a low-temperature coolant, ethylene glycol aqueous solution, which efficiently utilizes the cold energy of the LNG ship and ensures the long-term stability of the hydrate.

[0030] The storage module uses an intelligent temperature and pressure control system to monitor and adjust the temperature of each module in real time.

[0031] Each storage compartment of the storage module is equipped with an independent electric door 24, which adopts a sliding or flip-top structure, and the opening and closing is driven by an actuator motor. The storage module also provides a real-time visual interface 22, which displays the status of each storage compartment, such as idle, full, or loading, and allows manual handling 23 or automatic switching of storage compartments.

[0032] The storage unit 12 is equipped with pulleys 21, which can easily move between the cold storage compartment, the compression unit and the transportation area, reducing the limitations of fixed storage. The LNG cold energy supply and refrigeration unit includes a cold storage compartment 18 and a heat exchanger. The first heat exchanger 14 is mainly used to exchange heat for the cold storage compartment 18. The second heat exchanger 15 is connected to the cooling pipes built into the storage unit 12 and is mainly used to provide cooling capacity to the storage unit. The first LNG storage tank 16 is connected to the first heat exchanger 14 and the second heat exchanger 15 is connected to the second LNG storage tank 17.

[0033] All containers used for hydrate storage and transportation are coated with a specialized anti-stick coating. This hydroxyl-containing superhydrophobic coating inhibits hydrate nucleation and prevents hydrate adhesion, significantly reducing the adhesion of hydrates to the container surface. This prevents hydrates from adhering to the equipment's inner walls during compression, storage, and transportation, reducing energy consumption, maintenance costs, and improving system operating efficiency.

[0034] The safety and monitoring unit includes a temperature monitoring system 13 and a pressure monitoring system 8. The temperature monitoring system 13, installed in the cold storage compartment 18, is used to ensure that the internal temperature of the cold storage compartment 18 is maintained within the stable temperature range of the hydrate. The pressure monitoring system 8, installed on the canister compressor 9, is used to adjust the pressure during the compression process according to the morphology of the hydrate. Example 1

[0035] Figure 1 This is a carbon dioxide hydrate compression device based on the utilization of LNG ship cold energy, including a carbon dioxide hydrate generation unit, a carbon dioxide hydrate compression unit, a transportation unit, an LNG cold energy supply and refrigeration unit, and a safety and detection unit, specifically including the following steps:

[0036] S1. Carbon dioxide in the flue gas is converted into carbon dioxide slurry hydrate in the reactor 1 under high pressure and low temperature. The remaining reaction solution is recycled to the hydrate solution recovery tank 2. The slurry hydrate enters the carbon dioxide hydrate compression unit through the solid-liquid separator 4.

[0037] S2. Open the first discharge port valve 6 and the second discharge port valve 7. The hydrate slurry is introduced into the tank compressor 9 by gravity through the discharge port, and compressed into a cake or block hydrate. During the compression process, the temperature is always kept within the stable range of the hydrate.

[0038] S3. The hydrate mold cavity 10 containing blocky hydrates is transferred to the storage device 12 using the spiral conveyor belt 11 in the transport unit;

[0039] S4. The compressed carbon dioxide hydrate cake is transported from the compression unit to the inlet of the storage device 12 via the transport unit. The bottom of the storage device is equipped with a moving pulley 21 and an automatic docking device. The hydrate cake is sequentially introduced into an independent storage compartment. Each compartment is equipped with a flexible compression plate 19. The electric door 24 of the storage compartment is automatically opened and closed by the intelligent control system. After the hydrate cake is loaded, the compartment is automatically sealed to maintain a low temperature environment.

[0040] S5. When unloading or transportation is required, the storage device unlocks the pulleys and moves to the target area to achieve automated operation and ensure that the storage and transportation process is efficient and safe;

[0041] The compression, transportation, and storage of carbon dioxide hydrate are all carried out in the cold storage room 18, and the LNG storage tank transfers cold energy to the cold storage room 18 through a heat exchanger.

Claims

1. A carbon dioxide hydrate compression device based on LNG ship cold energy utilization, characterized in that: The compression unit includes a carbon dioxide hydrate generation unit, a carbon dioxide hydrate compression unit, a transportation unit, an LNG cold energy supply and refrigeration unit, and a safety and monitoring unit. The reaction vessel (1) in the carbon dioxide hydrate generation unit is connected to the solid-liquid separator (4) and the hydrate solution recovery tank (2), respectively. The solid-liquid separator (4) is connected to the tank compressor (9) in the carbon dioxide hydrate compression unit via a discharge pipe equipped with a valve. The outlet of the canister compressor (9) is connected to the inlet of the storage device (12) via a spiral conveyor belt (11) in the transport unit, and the spiral conveyor belt (11) transports the hydrate mold cavity (10). Each storage module in the storage device (12) is an independent box-type unit, which is divided into multiple storage compartments. Each storage compartment is used to store block hydrates. Cooling pipes (20) are embedded in each storage module and connected to the second heat exchanger (15) in the LNG cold energy supply and refrigeration unit. The storage module is monitored in real time by temperature sensors (25) and pressure sensors (26). Each storage compartment of the storage module is equipped with an independent electric door (24). Flexible compression plates (19) are configured after each row of storage compartments to ensure that the block hydrates are stable in the storage compartments. The storage module provides a real-time visualization interface (22) to display the status of each storage compartment. The bottom of the storage device (12) is equipped with moving pulleys (21) and an automatic docking device. The LNG cold energy supply and refrigeration unit includes a refrigeration chamber (18), a first heat exchanger (14) and a second heat exchanger (15). The first heat exchanger (14) is used to exchange heat with the refrigeration chamber (18). The second heat exchanger (15) is connected to the cooling pipe built into the storage device (12) and is used to provide cooling capacity to the storage device. The first LNG storage tank (16) is connected to the first heat exchanger (14), and the second heat exchanger (15) is connected to the second LNG storage tank (17). The compression unit, transport unit, and storage device are all located in the cold storage compartment (18).

2. The compression device according to claim 1, characterized in that: The electric door (24) adopts a sliding or flip-top structure, and the switch is driven by an actuator; the storage compartment is equipped with a manual handle (23).

3. The compression device according to claim 1, characterized in that: The safety and monitoring unit includes a temperature monitoring system (13) and a pressure monitoring system (8); the temperature monitoring system (13) installed in the cold storage compartment (18) is used to ensure that the internal temperature of the cold storage compartment (18) is maintained within the stable temperature range of the hydrate; the pressure monitoring system (8) installed on the canister compressor (9) is used to adjust the pressure during the compression process according to the morphology of the hydrate.

4. A method for storing carbon dioxide hydrate based on the utilization of cold energy from LNG ships, characterized in that, The storage method employs the compression device described in any one of claims 1-3; the storage method includes the following steps: S1. Carbon dioxide in the flue gas is converted into carbon dioxide slurry hydrate in the reactor (1) under high pressure and low temperature. The remaining reaction solution is recycled to the hydrate solution recovery tank (2). The slurry hydrate is filtered to remove impurities by the solid-liquid separator (4) and enters the carbon dioxide hydrate compression unit. S2. The hydrate slurry is introduced into the tank compressor (9) by gravity through the discharge port and compressed into block hydrate. During the compression process, the temperature is always controlled within the stable range of the hydrate. S3. The compressed block carbon dioxide hydrate is transported from the carbon dioxide hydrate compression unit to the inlet of the storage device (12) by the transport unit. The moving pulley and the automatic docking device ensure that the storage device is aligned with the transport unit. The block carbon dioxide hydrate is sequentially introduced into the independent storage compartments. The electric door (24) of the storage compartment is automatically opened and closed by the intelligent control system. After the block hydrate is loaded, the storage compartment is sealed to maintain a low temperature environment. When unloading or transportation is required, the storage device (12) unlocks the pulley (21) and moves to the target area to realize automated operation. The compression, transportation and storage of carbon dioxide hydrate are all carried out in the cold storage room (18), and the first LNG storage tank (16) transfers cold energy to the cold storage room (18) through the first heat exchanger (14).

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