Ship co2 hydrate capture system and method using waste heat and osmotic energy

Abstract

The application provides a ship CO2 hydrate capture system and method using waste heat energy and osmotic energy. The system comprises: a tail gas pretreatment module for sequentially performing cooling treatment, oxidation dust removal treatment and desulfurization and denitrification treatment on ship tail gas; a waste heat energy-osmotic energy power generation module for storing electric energy generated by organic Rankine cycle waste heat power generation and osmotic power generation; a hydrate method carbon capture module for bubbling and strengthening CO2 hydrate generation of flue gas after the tail gas pretreatment module, and forming hydrate slurry after CO2 hydrate accumulation, wherein a part of the hydrate slurry is subjected to CO2 capture, heating and pressure relief decomposition to produce purified water, and pure CO2 gas and purified water are obtained; another part of the hydrate slurry is subjected to filtration to obtain CO2 hydrate solid and storage; a CO2 transfer, utilization and storage module is used for directly storing the pure CO2 gas and the CO2 hydrate solid into the ocean or geology, or transporting the pure CO2 gas and the CO2 hydrate solid to downstream users for industrial utilization or biological utilization.

Description

Technical Field

[0001] This invention relates to the fields of hydrate application technology and environmental protection technology, specifically to a ship carbon dioxide hydrate capture system and method that utilizes waste heat energy and permeation energy. Background Technology

[0002] As one of the most significant greenhouse gases, global CO2 emissions reached 36.3 billion tons by 2021. my country, currently the world's largest emitter of CO2, emitted approximately 10 billion tons in 2021, facing immense pressure to reduce emissions.

[0003] With my country's rapid economic growth, the shipping industry has become increasingly developed, with 90% of my country's total import and export cargo transportation utilizing ocean transport. By the end of 2020, my country had 126,800 transport vessels with a net deadweight tonnage of 270.6016 million tons. However, with the rapid increase in the number of ships, the contribution of ship exhaust to atmospheric CO2 concentration is also constantly rising. Therefore, in the context of global carbon neutrality, carbon reduction in shipping is inevitable. In recent years, the global water transport industry's average annual greenhouse gas emissions have been approximately 900 million tons of CO2 equivalent, accounting for about 2.6% of global greenhouse gas emissions. If current trends continue, by 2050, carbon emissions from the water transport industry will double. Carbon reduction and energy recovery in shipping have become inevitable trends in shipping development.

[0004] For most centralized CO2 emissions, the costs incurred during capture, concentration, transportation, or storage are the key expenses in CO2 capture and storage. Solving the dual problems of exhaust gas treatment and energy consumption in shipping is of great significance for engineering applications. Common post-combustion CO2 capture technologies include chemical absorption, physical absorption, adsorption, and membrane separation. Chemical absorption is relatively mature and suitable for low CO2 concentrations at normal pressure, but it suffers from drawbacks such as large absorbent consumption, high reagent requirements, and high regeneration costs. While membrane separation is simple and easy to implement, it has high requirements for the feed gas, requiring pretreatment, dehydration, and filtration. Furthermore, the current manufacturing and regeneration costs of separation membranes are very high, making engineering applications difficult. Therefore, there is an urgent need for methods and equipment with high capture efficiency and low capture costs.

[0005] Carbon capture and storage (CCS) using hydrates has garnered significant attention from the academic community due to its immense capture potential. Clathrate hydrates are cage-like crystalline inclusions formed by water molecules bonded together by hydrogen bonds, enclosing gas molecules within the lattice. These white crystals, resembling dense ice and snow, are formed under specific temperature and pressure conditions. Common hydrate-forming substances include carbon dioxide, methane, ethane, and propane. The principle behind CO2 capture in ships based on hydrates is that the phase equilibrium differences during the formation of hydrates from binary and multi-component gases are substantial. Therefore, gases more prone to forming hydrates enter the hydrate phase, while those less likely to form hydrates remain in the gas phase, thus achieving the separation of the mixed gases.

[0006] The CO2 capture and storage technology using hydrates has significant potential. Firstly, under standard conditions, one cubic meter of CO2 hydrate can capture 164 cubic meters of CO2, requiring only 0.9 cubic meters of fresh or seawater. Secondly, CO2 hydrates are ice-like solids with a "self-protective" effect, allowing for storage under mild conditions; the technology is technically simple and easy to implement. Finally, CO2 hydrate formation conditions are mild; at a formation temperature of 2°C, only 2 MPa of pressure is needed to generate large quantities of hydrates. This is much milder and more energy-efficient than the 3.7 MPa or higher pressure required by liquefaction methods.

[0007] Carbon emission reduction and energy recovery in shipping have become an inevitable trend in shipping development. Currently, there is no satisfactory solution worldwide for coupling ship exhaust gas treatment with clean energy. On the one hand, domestic and international attention is mainly focused on research into removing nitrogen oxides using methods such as selective catalytic reduction (SCR), while relatively little attention is paid to the capture and storage of the large amounts of CO2 emitted from ships. Current CO2 treatment solutions for ship exhaust gas remain simplistic and crude, generally involving direct emission into the atmosphere. On the other hand, ship exhaust gas treatment is extremely energy-intensive, and there is currently no method that perfectly couples waste heat power generation, infiltration power generation, and carbon capture using hydrates. Summary of the Invention

[0008] To address the aforementioned technical problems, this invention provides a ship carbon dioxide hydration capture system and method utilizing waste heat energy and permeation energy. The aim is to explore new solutions for ship energy recovery and utilization, improve exhaust gas CO2 capture efficiency to achieve carbon emission reduction and carbon sequestration, and generate significant environmental and economic benefits.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0010] This invention provides a ship carbon dioxide hydrate capture system utilizing waste heat energy and permeation energy. The system includes: a connected exhaust gas pretreatment module, a waste heat energy-permeation energy power generation module, a hydrate-based carbon capture module, and a CO2 transfer, utilization, and storage module. The exhaust gas pretreatment module sequentially performs cooling, oxidation dust removal, and desulfurization / denitrification treatments on the ship's exhaust gas. The waste heat energy-permeation energy power generation module stores the electrical energy generated by organic Rankine cycle waste heat power generation and permeation energy power generation to power the hydrate-based carbon capture module. The hydrate-based carbon capture module is used to transfer, utilize, and store the CO2 from the exhaust gas. The flue gas pretreatment module enhances the generation of CO2 hydrate through bubbling. The CO2 hydrate aggregates to form a hydrate slurry. A portion of the hydrate slurry is subjected to CO2 capture and heated for decomposition to produce purified water, yielding pure CO2 gas and purified water. Another portion of the hydrate slurry is filtered to obtain CO2 hydrate solids, which are then stored. The CO2 transfer, utilization, and storage module is used to directly seal the pure CO2 gas and CO2 hydrate solids in the ocean or geological formations, or transport them to downstream users for industrial or biological utilization.

[0011] Furthermore, the exhaust gas pretreatment module includes a heat exchanger, a pretreatment device, a first scrubbing tower, and a second scrubbing tower connected in sequence. The heat exchanger is used to cool the ship exhaust gas so that the high-temperature and high-pressure ship exhaust gas with a temperature of 350℃~400℃ can be used for power generation, and to cool it down to below 45℃. The pretreatment device is used to oxidize the cooled ship exhaust gas with ozone and remove impurities with dust collection bags. The first and second scrubbing towers are used to desulfurize and denitrify the ship exhaust gas after oxidation and dust removal treatment, and to obtain a washing liquid.

[0012] Furthermore, the hydrate-based carbon capture module includes a CO2 hydrate bubble generator, a hydrate filter / decomposer, and an integrated hydrate filter / storage device. The CO2 hydrate bubble generator is used to enhance the generation of hydrates by bubbling CO2 gas. Since the density of hydrates is less than that of concentrated brine, they accumulate at the top of the CO2 hydrate bubble generator to form a slurry with a high hydrate phase fraction. The hydrate filter / decomposer is used to capture CO2 in the hydrate slurry and heat and depressurize it to produce purified water. The integrated hydrate filter / storage device is used to filter out the CO2 hydrate solids in the hydrate slurry and then compact and store the CO2 hydrate solids.

[0013] Furthermore, the CO2 hydrate bubbling generator includes a hollow generator body, with a bubbling plate at the bottom inside the generator body; a concentrated brine outlet and a seawater inlet are respectively opened at the bottom of the generator body; a hydrate slurry outlet is opened at the top, and an exhaust port is opened above the hydrate slurry outlet.

[0014] Furthermore, the hydrate filter / decomposer includes a decomposer body, with a compaction plate at the top and a hydrate solid filter plate at the bottom inside the decomposer body; a concentrated brine or fresh water outlet is provided on the decomposer body below the hydrate solid filter plate; a hydrate slurry inlet and a pure CO2 gas outlet are respectively provided on the decomposer body between the compaction plate and the hydrate solid filter plate; wherein, the integrated hydrate filtration / storage device has the same structure as the hydrate filter / decomposer; the operating conditions of the hydrate filter / decomposer are normal temperature and pressure, specifically 20-25℃ and 0.1MPa; the operating conditions of the integrated hydrate filtration / storage device are low temperature and high pressure, specifically 2-8℃ and 1-5MPa.

[0015] Furthermore, the CO2 hydrate bubbling generator, hydrate filter / decomposer, and integrated hydrate filter / storage device are all equipped with visual windows for observing the hydrate status; the CO2 hydrate bubbling generator, hydrate filter / decomposer, and integrated hydrate filter / storage device are all equipped with temperature and pressure sensors for monitoring the temperature and pressure inside the equipment; and the CO2 hydrate bubbling generator, hydrate filter / decomposer, and integrated hydrate filter / storage device are all equipped with safety valves to maintain the pressure inside the equipment within a set range.

[0016] Furthermore, the system also includes a data acquisition and control module, which is used to acquire data from the temperature and pressure sensors installed in the hydrate carbon capture module, and simultaneously electrically control the compaction plate to compact the CO2 hydrate solids.

[0017] Furthermore, the waste heat energy-permeable energy power generation module includes an organic Rankine cycle waste heat generator set, a permeable energy power generation battery, and a battery bank; the organic Rankine cycle waste heat generator set is used to generate electricity using high-temperature ship exhaust gas; the permeable energy power generation battery is used to generate electricity using washing liquid, concentrated brine filtered from a CO2 hydrate bubbling generator, a hydrate filter / decomposer, and an integrated hydrate filter / storage device, and purified water produced by heating and depressurizing the hydrate filter / decomposer; the battery bank is used to store the electrical energy generated by the organic Rankine cycle waste heat generator set and the permeable energy power generation battery, and to supply power to the hydrate-based carbon capture module.

[0018] Furthermore, the system also includes a solid-liquid separator disposed before the permeation energy generation cell, the solid-liquid separator being used to separate solids and impurities in the hydrate slurry.

[0019] This invention also provides a method for capturing carbon dioxide hydrate from ships using waste heat and permeation energy, comprising: sequentially cooling, oxidizing and removing dust from ship exhaust gas, and then desulfurizing and denitrifying it; storing the electrical energy generated by organic Rankine cycle waste heat power generation and permeation energy power generation to power the hydrate-based carbon capture module; bubbling and strengthening the flue gas from the exhaust gas pretreatment module to generate CO2 hydrate, which then aggregates to form a hydrate slurry; wherein a portion of the hydrate slurry is subjected to CO2 capture and heated and depressurized to produce purified water, yielding pure CO2 gas and purified water; another portion of the hydrate slurry is filtered to obtain CO2 hydrate solid, which is then stored; the pure CO2 gas and CO2 hydrate solid are directly sealed in the ocean or geological formations, or transported to downstream users for industrial or biological utilization.

[0020] Compared with the prior art, the technical solution provided by the present invention has at least the following advantages:

[0021] This invention designs a shipboard carbon dioxide hydration capture system and method utilizing waste heat energy and osmotic energy. It is energy-saving, emission-reducing, simple, highly efficient, and reliable, suitable for ship energy recovery and exhaust gas treatment. Specifically:

[0022] ① Improve energy recovery and utilization rate. The electrical energy consumed by the hydrate generator is covered by waste heat energy and infiltration energy generation, without consuming ship electricity, basically achieving "zero carbon" electricity and saving the ship's energy consumption by about 25%.

[0023] ② Improve CO2 capture efficiency. Compared with other capture methods, CO2 capture using hydrates can achieve a tail gas treatment efficiency of over 95%, purifying CO2 to achieve carbon emission reduction and carbon sequestration. It can also realize the effective utilization or permanent storage of some or all CO2, opening up new solutions for ship tail gas treatment and generating huge environmental and economic benefits.

[0024] ③ High economic benefits. This design makes full use of waste heat and infiltration energy for power generation, and makes full use of natural resources such as seawater, which greatly reduces the cost of ship exhaust treatment and energy consumption. It can be used in ship systems of any size and is undoubtedly a new way to promote the construction of "green shipping". Attached Figure Description

[0025] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations do not constitute a limitation on the embodiments, and unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0026] Figure 1 This is a schematic diagram of a ship carbon dioxide hydration capture method utilizing waste heat energy and permeation energy provided by the present invention.

[0027] Figure 2 This is a flowchart of a ship carbon dioxide hydration capture system utilizing waste heat energy and permeation energy provided by the present invention;

[0028] Figure 3 This is a schematic diagram of the structure of a CO2 hydrate bubbling generator in a ship carbon dioxide hydrate capture system that utilizes waste heat energy and permeation energy, provided by the present invention.

[0029] Figure 4 This is a schematic diagram of the structure of a hydrate filter / decomposer (integrated hydrate filter / storage device) in a ship carbon dioxide hydrate capture system utilizing waste heat energy and permeation energy, provided by the present invention.

[0030] In the diagram, 1-Ship exhaust outlet; 2-Shell-tube heat exchanger; 3-Pretreatment unit; 4-First scrubbing tower; 5-Second scrubbing tower; 6-Organic Rankine Cycle (ORC) waste heat power generation unit; 7-Solid-liquid separator; 8-Permeable energy generator; 9-Battery bank; 10-CO2 hydrate bubbling generator; 11-Hydrate filter / decomposer; 12-Hydrate filter / storage integrated unit; 13-High-pressure gas injection pump; 14-Computer; 15-Seawater pump; 16-Three-way valve; 17-Control valve; 18-Check valve; 19-Exhaust valve. 20-Safety valve; 21-Electric valve; 22-Needle valve; 23-Temperature sensor; 24-Pressure sensor; 25-Bubble plate; 26-Glass window; 27-CO2 hydrate slurry; 28-Concentrated brine outlet; 29-Seawater inlet; 30-Hydrate slurry outlet; 31-Exhaust port; 32-Concentrated brine or fresh water outlet; 33-Pure CO2 gas outlet; 34-Compactor plate; 35-Hydrate slurry inlet; 36-Hydrate solid filter plate; 37-CO2 hydrate solid; 38-Transport vehicle; 39-Concentrated brine tank; 40-Purified water tank;

[0031] G-1:CO X, SO X NO X VOC S G-2: A mixture of gases including H2O and N2; G-3: A mixture of gases including CO2, N2, NO2, and SO2; G-4: A mixture of gases including CO2 and N2; G-5: N2. Detailed Implementation

[0032] As the background technology indicates, there is currently no satisfactory solution worldwide for coupling ship carbon reduction and clean energy in existing ship exhaust treatment solutions. On the one hand, the focus both domestically and internationally is primarily on research into removing nitrogen oxides using methods such as selective catalytic reduction (SCR), while relatively little attention has been paid to the capture and storage of the large amounts of CO2 emitted from ships. Current CO2 treatment solutions for ship exhaust remain simplistic and crude, generally involving direct emission into the atmosphere. On the other hand, ship exhaust treatment is extremely energy-intensive, and there is currently no method that perfectly couples waste heat power generation, infiltration power generation, and hydrate-based carbon capture.

[0033] Currently, Zhang Peng et al. (patent number CN 115318078 A) and Li Wenzhao et al. (patent number CN 105080323 A) have proposed a method for rapidly capturing carbon dioxide from waste gas using the hydrate method, mainly used in factories. However, the CO2 capture efficiency is not high and additional energy consumption is required. Song Yongchen et al. (patent number CN 114806660 A) and Liu Yang et al. (patent number CN114618381 A) have proposed a method for coupling carbon capture with hydrate method and cold storage, which uses the captured CO2 to generate hydrates and then utilizes them in the refrigeration field, reducing energy consumption to a certain extent. He Junnan et al. (patent number CN 105797541B) designed a solar photovoltaic driven hydrate method carbon capture system, but the high uncertainty of marine weather will affect the continuity of power supply. The energy recovery method in this design is more reliable, more stable, and lower in cost.

[0034] In view of this, the present invention is proposed. The present invention designs a CO2 ship exhaust gas capture process based on the principle of hydrate carbon capture, and achieves the removal of other harmful components in ship exhaust gas and the recovery and reuse of energy by coupling waste heat power generation, osmotic pressure power generation and other technologies.

[0035] In summary, the present invention has the following advantages:

[0036] ① Existing hydrate-based carbon capture systems are generally designed for land-based facilities such as factories and coal-fired plants, with few designs specifically for carbon capture systems on ships at sea;

[0037] ② Compared to land-based carbon capture systems, shipboard carbon capture systems have more stringent requirements regarding low energy consumption, small footprint, and high carbon capture efficiency, and are more easily integrated with natural seabed carbon storage technologies. This invention meets the above requirements.

[0038] ③ This invention fully considers the application scenarios of ship carbon capture systems and for the first time perfectly couples hydrate carbon capture with permeable energy power generation, reducing energy consumption; it also makes full use of seawater natural resources and reduces the waste of freshwater resources.

[0039] ④ The original design of this invention is applicable to sub-devices of the system, such as permeable energy generation batteries coupled with hydrate carbon capture, CO2 hydrate bubbling generators, integrated hydrate filtration and storage devices, etc.

[0040] ⑤ This invention is the first to design a novel and compact shipborne energy recovery and carbon capture, utilization and storage (CCUS) system, which can be used in ship systems of any size.

[0041] This invention provides a shipboard carbon dioxide hydrate capture system utilizing waste heat energy and permeation energy. The system includes: a connected exhaust gas pretreatment module, a waste heat energy-permeation energy power generation module, a hydrate-based carbon capture module, and a CO2 transfer, utilization, and storage module. The exhaust gas pretreatment module sequentially performs cooling, oxidation dust removal, and desulfurization / denitrification treatments on the ship's exhaust gas. The waste heat energy-permeation energy power generation module stores the electrical energy generated by organic Rankine cycle waste heat power generation and permeation energy power generation to power the hydrate-based carbon capture module. The hydrate-based carbon capture module is used to transfer, utilize, and store the CO2 from the exhaust gas. The exhaust gas pretreatment module enhances the generation of CO2 hydrate through bubbling. The CO2 hydrate aggregates to form a hydrate slurry. A portion of the hydrate slurry is subjected to CO2 capture and heated for decomposition to produce purified water, yielding pure CO2 gas and purified water. Another portion of the hydrate slurry is filtered to obtain CO2 hydrate solids, which are then stored. The CO2 transfer, utilization, and storage module is used to directly seal the pure CO2 gas and CO2 hydrate solids in the ocean or geological formations, or transport them to downstream users for industrial or biological utilization.

[0042] Specific connection relationship: A ship carbon dioxide hydrate capture system utilizing waste heat energy and permeation energy, including an exhaust gas pretreatment module, a waste heat energy-permeation energy power generation module, a hydrate carbon capture module, a data acquisition and control module, and a CO2 transfer, utilization and storage module.

[0043] ① The exhaust gas pretreatment module first releases heat from the high-temperature, high-pressure ship exhaust gas (350-400℃) emitted from the ship's exhaust outlet 1 in a shell-and-tube heat exchanger 2. This heat is then used to generate electricity for the organic Rankine cycle waste heat generator set 6. The cooled exhaust gas temperature is below 45℃, G-1:CO X SO X NO X VOCs, H2O, N2, etc. are then fed into the pretreatment unit 3, where ozone is used to oxidize the waste gas and dust collector bags are used to remove impurities, resulting in G-2: a mixture of CO2, N2, NO2, and SO2. Subsequently, the gas is desulfurized and denitrified in two processes, the first scrubbing tower 4 and the second scrubbing tower 5, to obtain G-3: CO2 and N2.

[0044] The waste heat energy-permeable energy power generation module mainly stores the electrical energy generated by organic Rankine cycle waste heat power generation and permeable energy power generation in the battery pack 9 to supply power to the hydrate method carbon capture module.

[0045] The hydrate-based carbon capture module first introduces the treated flue gas into a CO2 hydrate bubbling generator 10. The CO2 gas, after passing through a high-pressure gas injection pump 13, is then bubbled through a bottom bubbling plate 25 to enhance hydrate formation. The water required for hydrate formation comes from seawater. CO2 and water react under high pressure and low temperature (2–8°C, 1–5 MPa) conditions to form a hydrate slurry 27. Under these temperature and pressure conditions, N2 does not participate in hydrate formation and the slurry is discharged into the atmosphere through an exhaust port 31.

[0046] Subsequently, part of the hydrate slurry 27 enters the hydrate filter / decomposer 11, and part enters the integrated hydrate filter / storage device 12. (Note: The hydrate filter / decomposer 11 and the integrated hydrate filter / storage device 12 are identical in design, differing only in function, and can be converted between each other.) The CO2 hydrate in the hydrate filter / decomposer 11 is mainly used for heating and decomposing to produce purified water 40 and obtain pure CO2 gas. The purified water enters the purified water pool 40 in the permeable energy power cell 8 to participate in salinity gradient power generation. The integrated hydrate filter / storage device 12 is mainly used to filter out CO2 hydrate solids, which are then compacted and stored in the device for easy subsequent transfer. Both the pure CO2 gas and CO2 hydrate solids obtained in this module can be used for subsequent CO2 transfer, utilization, and storage.

[0047] The CO2 hydrate bubbling generator 10, hydrate filter / decomposer 11, and hydrate filter / storage integrated device 12 are all equipped with a visual window 26 for easy observation of the hydrate status. Temperature sensor 23 and pressure sensor 24 facilitate monitoring of the temperature and pressure inside the equipment. Safety valve 20 maintains the pressure inside the equipment within a set range.

[0048] The data acquisition and control module mainly acquires data from the temperature sensor 23 and pressure sensor 24 of the hydrate carbon capture module, and simultaneously uses electric control to compact the CO2 hydrate solid 37 of the compaction plate 34.

[0049] The CO2 transfer, utilization and storage module can directly store CO2 hydrates in the ocean or geological formations, or transport them by transport vehicle 38 to downstream users for industrial or biological utilization.

[0050] The present invention will now be described in detail with reference to specific embodiments.

[0051] Figure 1The diagram shows a schematic of a shipboard carbon dioxide hydration capture method utilizing waste heat energy and osmotic energy. The workflow is as follows: ① First, flue gas G-1: CO... X SO X NO X VOCs, H2O, N2, etc., are transferred to the organic Rankine cycle waste heat generator set 6 for power generation via the shell-and-tube heat exchanger 2. The cooled flue gas is converted into G-2: a mixture of CO2, N2, NO2, and SO2 after being oxidized by ozone and purged by dust collectors in the pretreatment device. Then, it is converted into G-3: CO2 and N2 after being treated by the first scrubbing tower 4 and the second scrubbing tower 5. The scrubbing water containing concentrated nitrates and sulfates obtained from the scrubbing towers enters the concentrated brine pool 39 of the permeable energy power cell 8 to participate in salinity gradient power generation. ② The G-3 mixture enters the CO2 hydrate bubbling reactor 10, where CO2 and water form a hydrate slurry under high pressure and low temperature, and N2 is discharged into the atmosphere. ③ A portion of the hydrate slurry enters the integrated hydrate filtration / storage device 12 through pipelines. After filtration and compaction, CO2 hydrate solids are obtained and stored in the device for subsequent transfer, utilization, or sealing. A portion of the hydrate slurry is first filtered in the hydrate filter / decomposer 11, and the concentrated brine enters the concentrated brine tank 39 of the permeation energy power cell 8. Then, the hydrate solids are heated and depressurized to obtain purified water and CO2 gas. The purified water enters the purified water tank 40 of the permeation energy power cell 8, and the CO2 gas is stored in the device for subsequent transfer or utilization. ④ The hydrate-based carbon capture module requires a high-pressure, low-temperature environment. The electrical energy generated by waste heat and permeation energy is stored in the battery pack 9 and then used to power the equipment in the hydrate-based carbon capture module, ultimately obtaining pure CO2 hydrate and pure CO2 gas, which will then be transferred, utilized, or sealed. ⑤ Simultaneously, the data acquisition and control system (computer 14) collects, monitors, and controls the process flow to improve system reliability.

[0052] Figure 2 The diagram shows a flowchart of a shipboard carbon dioxide hydration capture system utilizing waste heat and infiltration energy. The detailed scheme is as follows:

[0053] First, the ship's exhaust gas G-1, with a temperature of 350-400℃, exchanges heat with the working fluid of the organic Rankine cycle waste heat generator set 6 through the shell-and-tube heat exchanger 2, cooling the exhaust gas to below 45℃. It then enters the pretreatment unit 3 where ozone oxidizes NO and CO, and dust collector bags remove VOCs, yielding G-2. The basic reaction principle is as follows:

[0054]

[0055] Seawater is injected into the washing towers (first washing tower 4 and second washing tower 5) by opening control valve 17 and seawater pump 15. G-2 is processed by the first washing tower 4 and the second washing tower 5 to obtain G-3. The concentrated brine containing sulfate and nitrate obtained after washing enters the concentrated brine pool 39 in the permeable energy power cell 8 to participate in power generation. Check valve 18 and valve ports a and b of three-way valve 16 are opened. G-3 is pressurized to 2-5 MPa by high-pressure gas injection pump 13. Electric valve 21 and needle valve 22 are opened to control the gas injection flow rate of G-3. G-3 enters the CO2 hydrate bubbling generator 10, and the pressure inside the container increases. The G-3 mixture contains CO2 and N2, with the proportion of CO2 exceeding 80%. At this time, the partial pressure of CO2 exceeds the phase equilibrium pressure of CO2 at the generation temperature and maintains a certain degree of subcooling.

[0056] Figure 3 The diagram shows a CO2 hydrate bubbling generator device. The CO2 hydrate bubbling generator 10 includes a hollow generator body, and a bubbling plate 25 is provided at the bottom of the generator body. The bottom of the generator body is provided with a concentrated brine outlet 28 and a seawater inlet 29. The top is provided with a hydrate slurry outlet 30 and an exhaust port 31 above the hydrate slurry outlet 30.

[0057] Seawater is injected into the generator by opening control valve 17 and seawater pump 15. G-3 bubblees through bottom bubble plate 25 to enhance hydrate formation. As the bubbles rise, hydrate shells form on their outer shells, continuously consuming water and increasing the seawater salt concentration in the generator. Because CO2 hydrate bubbles are less dense than seawater, they accumulate at the top of the generator under buoyancy. The three-way valve 16 is opened to discharge the top hydrate slurry to downstream devices. Top safety valve 20 maintains constant pressure inside the generator, and N2 is released into the atmosphere after opening exhaust valve 19. Due to the "salt discharge effect" of the hydrate formation process, the salinity of the remaining seawater will significantly increase, becoming concentrated brine. The one-way valve 18 on the concentrated brine outlet pipe 28 is opened to discharge the concentrated brine to the concentrated brine pool 39 of the permeable energy generator 8.

[0058] Figure 4The diagram shows a hydrate filter / decomposer 11 and a hydrate filter / storage integrated device 12. The hydrate filter / decomposer 11 includes a decomposer body, with a compaction plate 34 at the top and a hydrate solid filter plate 36 at the bottom. A concentrated brine or fresh water outlet 32 ​​is located below the hydrate solid filter plate 36 on the decomposer body. A hydrate slurry inlet 35 and a pure CO2 gas outlet 33 are located between the compaction plate 34 and the hydrate solid filter plate 36 on the decomposer body. It should be noted that the hydrate filter / storage integrated device 12 has the same structure as the hydrate filter / decomposer 11. The operating conditions of the hydrate filter / decomposer 11 are ambient temperature and pressure (20–25°C, 0.1 MPa); the operating conditions of the hydrate filter / storage integrated device 12 are low temperature and high pressure (2–8°C, 1–5 MPa).

[0059] Open all ports of the three-way valve 16 to allow part of the CO2 hydrate slurry to enter the hydrate filter / decomposer 11 and part to enter the integrated hydrate filter / storage device 12. In the hydrate filter / decomposer 11, open the check valve 18 and ports a and c of the three-way valve 16 to allow the concentrated brine entrained in the hydrate solids to be filtered on the hydrate solids filter plate 36 and then enter the concentrated brine tank 39. Then close port a of the three-way valve 16 and open port b, place the decomposer 11 at room temperature (20-25°C) and depressurize it to atmospheric pressure, so that the hydrates decompose to obtain pure water and CO2 gas. The purified water enters the purified water tank 40 to participate in the osmotic energy power generation, and the CO2 gas can enter the hydrate generator 10 to regenerate hydrates, or it can be directly transferred and utilized. The integrated hydrate filter / storage device 12 has the same structure as the decomposer 11 but a different function. This device is only used to store CO2 hydrates. The CO2 gas entrained in the hydrates is circulated through outlet 33 to the hydrate generator 10 to regenerate hydrates.

[0060] In the waste heat energy-permeable energy power generation module, the electrical energy of battery pack 9 comes from two parts: the organic Rankine cycle waste heat generator set 6 and the permeable energy power generation battery 8. The basic principle of permeable energy power generation is as follows: a semi-permeable membrane separates water with different salt concentrations. Water molecules cannot pass through the membrane, but salt ions can. In this way, salt ions will continuously permeate from water with high salt concentration to water with low salt concentration until the salt concentrations of fresh water and salt water are the same. Since salt ions are charged, the movement of salt ions forms an electric current. The concentrated brine in the permeable energy power generation battery 8 comes from four parts: the washing liquid obtained from washing towers 4 and 5, the hydrate bubbling generator 10, the hydrate filter / decomposer 11, and the integrated hydrate filter / storage device 12; the solid-liquid separator 7 is mainly used to filter hydrate solids and impurities; the purified water comes from the decomposition of hydrate solids in the hydrate filter / decomposer.

[0061] The data acquisition and control system collects, monitors, and controls data such as temperature, pressure, and flow rate in real time, and controls the compaction plate 34 of the hydrate filtration / storage integrated device 12 to compact the loose CO2 hydrate solids.

[0062] The CO2 hydrate within the integrated hydrate filtration / storage device 12 decomposes at room temperature and is stored within the device as CO2 hydrate or in gaseous form, which can then be transported to other terminals. Several technological directions for carbon utilization are as follows: ① The CO2 hydrate within the integrated hydrate filtration / storage device 12 can be directly transported to marine or terrestrial CO2 sequestration sites to achieve CO2 hydrate sequestration; ② The high-purity CO2 (containing only CO2 gas and water vapor) within the integrated hydrate filtration / storage device 12 can be transported to industrial terminals via CO2 transport ships. With only simple processing, the high-purity CO2 can be used in industries such as alkali production, sugar production, plastics, and dry ice production; ③ In terms of biological utilization, artificial bioconversion technology integrating synthetic biology techniques can industrially convert CO2 into various amino acids, starch, biofuels, and other synthetic products needed by humans.

[0063] This solution is applicable to ship exhaust gas treatment, and can also be used in factories, coal-fired plants, waste incineration plants, and other places that require exhaust gas treatment after combustion.

[0064] The washing tower of the pretreatment module can be either open or closed.

[0065] In addition to using the bubbling method to enhance hydrate formation, hydrate generators can also employ mechanical methods such as stirring and spraying, or chemical methods such as adding thermodynamic or kinetic promoters.

[0066] The resulting CO2 hydrate can be directly stored in an integrated hydrate filtration / storage device and transported to downstream users or directly stored in the ocean, or it can be decomposed at room temperature to obtain pure CO2 gas and transported to the end user.

[0067] This invention also provides a method for capturing carbon dioxide hydrate from ships using waste heat energy and osmotic energy, comprising:

[0068] The ship's exhaust gas is sequentially treated with cooling, oxidation and dust removal, and desulfurization and denitrification.

[0069] The electrical energy generated by organic Rankine cycle waste heat power generation and infiltration energy power generation is stored to supply electricity to the hydrate carbon capture module;

[0070] The flue gas passing through the exhaust gas pretreatment module is bubbled and enhanced to generate CO2 hydrate. The CO2 hydrate is then aggregated to form a hydrate slurry. A portion of the solid hydrate is subjected to CO2 capture and heated and depressurized decomposition to produce purified water, resulting in pure CO2 gas and purified water. The other portion of the hydrate slurry is filtered to obtain CO2 hydrate solid, which is then stored.

[0071] The pure CO2 gas and CO2 hydrate solids can be directly sealed in the ocean or geological sites, or transported to downstream users for industrial or biological use.

[0072] Those skilled in the art will understand that the above-described embodiments are specific examples of implementing this application, and in practical applications, various changes in form and detail may be made without departing from the spirit and scope of this application. Any person skilled in the art can make their own modifications and alterations without departing from the spirit and scope of this application; therefore, the scope of protection of this application should be determined by the scope defined in the claims.

Claims

1. A shipboard carbon dioxide hydration capture system utilizing waste heat energy and osmotic energy, characterized in that, The system includes: a connected exhaust gas pretreatment module, a waste heat energy-permeable energy power generation module, a hydrate carbon capture module, and a CO2 transfer, utilization and storage module; The exhaust gas pretreatment module is used to sequentially perform cooling, oxidation and dust removal, and desulfurization and denitrification treatments on the ship's exhaust gas. The waste heat energy-permeable energy power generation module is used to store the electrical energy generated by organic Rankine cycle waste heat power generation and permeable energy power generation, so as to supply electricity to the hydrate method carbon capture module. The hydrate-based carbon capture module is used to enhance the generation of CO2 hydrate from the flue gas after passing through the exhaust gas pretreatment module by bubbling. The CO2 hydrate accumulates to form a hydrate slurry. A portion of the hydrate slurry is subjected to CO2 capture and heated and depressurized decomposition to produce purified water, resulting in pure CO2 gas and purified water. The other portion of the hydrate slurry is filtered to obtain CO2 hydrate solids, which are then stored. The CO2 transfer, utilization and storage module is used to directly seal the pure CO2 gas and CO2 hydrate solid to the ocean or geology, or transport them to downstream users for industrial or biological utilization. The exhaust gas pretreatment module includes a heat exchanger, a pretreatment device, a first scrubbing tower, and a second scrubbing tower connected in sequence. The heat exchanger is used to cool the ship exhaust gas so that the high-temperature and high-pressure ship exhaust gas with a temperature of 350℃~400℃ can be used for power generation, and the temperature is reduced to below 45℃. The pretreatment device is used to oxidize the cooled ship exhaust gas with ozone and remove impurities with dust collection bags. The first and second scrubbing towers are used to desulfurize and denitrify the ship exhaust gas after oxidation and dust removal treatment, and to obtain scrubbing liquid; The hydrate-based carbon capture module includes a CO2 hydrate bubbling generator, a hydrate filter / decomposer, and an integrated hydrate filter / storage device. The CO2 hydrate bubbler is used to enhance the bubbling of CO2 gas to generate hydrates. The density of hydrates is less than that of concentrated brine, so they accumulate at the top of the CO2 hydrate bubbler to form a slurry with a high hydrate phase fraction. The hydrate filter / decomposer is used to capture CO2 in the hydrate slurry and heat and depressurize it to produce purified water. The integrated hydrate filtration / storage device is used to filter out CO2 hydrate solids from the hydrate slurry and then store the CO2 hydrate solids after compaction. The CO2 hydrate bubbling generator includes a hollow generator body, and a bubbling plate is provided at the bottom of the generator body; The bottom of the generator body is provided with a concentrated brine outlet and a seawater inlet; the top is provided with a hydrate slurry outlet and an exhaust port located above the hydrate slurry outlet. The waste heat energy-permeable energy power generation module includes an organic Rankine cycle waste heat power generation unit, a permeable energy power generation battery, and a battery pack. The organic Rankine cycle waste heat generator set is used to generate electricity using high-temperature ship exhaust gas. The permeable energy power battery is used to generate electricity using washing liquid, concentrated brine filtered from a CO2 hydrate bubbling generator, a hydrate filter / decomposer and an integrated hydrate filter / storage device, and purified water produced by heating and depressurizing the hydrate filter / decomposer. The battery pack is used to store the electrical energy generated by the organic Rankine cycle waste heat generator and the permeable energy generator, and to supply power to the hydrate carbon capture module.

2. The ship carbon dioxide hydrate capture system utilizing waste heat energy and permeation energy as described in claim 1, characterized in that, The hydrate filter / decomposer includes a decomposer body, with a compaction plate at the top and a hydrate solid filter plate at the bottom inside the decomposer body. The decomposer body has a concentrated brine or fresh water outlet located below the hydrate solid filter plate; the decomposer body has a hydrate slurry inlet and a pure CO2 gas outlet located between the compaction plate and the hydrate solid filter plate. The integrated hydrate filtration / storage device has the same structure as the hydrate filtration / decomposer. The hydrate filter / decomposer operates under normal temperature and pressure conditions. The operating conditions of the integrated hydrate filtration / storage device are low temperature and high pressure.

3. The ship carbon dioxide hydrate capture system utilizing waste heat energy and permeation energy as described in claim 1 or 2, characterized in that, The CO2 hydrate bubbling generator, hydrate filter / decomposer, and hydrate filter / storage integrated device are all equipped with a visual window for observing the hydrate status; The CO2 hydrate bubbling generator, hydrate filter / decomposer, and hydrate filter / storage integrated device are all equipped with temperature sensors and pressure sensors to monitor the temperature and pressure inside the equipment. The CO2 hydrate bubbling generator, hydrate filter / decomposer, and hydrate filter / storage integrated device are all equipped with safety valves to maintain the pressure inside the equipment within a set range.

4. The ship carbon dioxide hydrate capture system utilizing waste heat energy and permeation energy as described in claim 2, characterized in that, The system also includes a data acquisition and control module, which is used to acquire data from the temperature and pressure sensors installed in the hydrate carbon capture module, and to electrically control the compaction plate to compact the CO2 hydrate solid.

5. The ship carbon dioxide hydrate capture system utilizing waste heat energy and permeation energy as described in claim 1, characterized in that, The system also includes a solid-liquid separator located upstream of the permeation energy generation cell, which is used to separate solids and impurities from the hydrate slurry.

6. A method for capturing carbon dioxide hydrate from ships using waste heat energy and osmotic energy, characterized in that, This method is applied to a shipboard carbon dioxide hydration capture system utilizing waste heat energy and permeation energy as described in any one of claims 1 to 5; comprising: The ship's exhaust gas is sequentially treated with cooling, oxidation and dust removal, and desulfurization and denitrification. The electrical energy generated by organic Rankine cycle waste heat power generation and infiltration energy power generation is stored to supply electricity to the hydrate carbon capture module; The flue gas passing through the exhaust gas pretreatment module is bubbled and enhanced to generate CO2 hydrate. The CO2 hydrate accumulates to form a hydrate slurry. A portion of the hydrate slurry is subjected to CO2 capture and heated and depressurized decomposition to produce purified water, resulting in pure CO2 gas and purified water. The other portion of the hydrate slurry is filtered to obtain CO2 hydrate solid, which is then stored. The pure CO2 gas and CO2 hydrate solids can be directly sealed in the ocean or geological sites, or transported to downstream users for industrial or biological use.

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