Methanol dual-fuel ship tail gas carbon capture and fuel regeneration system

Abstract

The invention discloses a methanol dual-fuel ship tail gas carbon capture and fuel regeneration system which comprises a seawater desalination device, a heat exchanger device and a heavy oil combustion device, wherein the heavy oil combustion device is used for performing heavy oil combustion, outputting energy to provide power for ship navigation and discharging combustion tail gas; the methanol combustion device is used for combusting methanol, outputting energy to provide power for sailing of the ship and discharging combustion tail gas; the tail gas treatment device is used for treating tail gas output by the heavy oil combustion device and the methanol combustion device and respectively discharging CO gas and CO2 gas; the methanol synthesis device is used for performing methanol synthesis on the basis of CO gas and CO2 gas output by the tail gas treatment device and high-temperature water output by the heat exchanger device, and transmitting methanol to the methanol combustion device; and the control system is used for realizing control on maximum carbon emission reduction benefits of ship navigation power and ship output tail gas by adjusting the tail gas treatment device and the methanol synthesis device based on the navigation state of the ship.

Description

Technical Field

[0001] This invention belongs to the field of marine environmental protection and new energy technology, and relates to a carbon capture and fuel regeneration system for methanol dual-fuel ship exhaust gas. Background Technology

[0002] Current ships primarily rely on diesel engines for power and emissions, generating large amounts of exhaust gases containing carbon dioxide and carbon monoxide. Current ship exhaust gas treatment technologies mainly include desulfurization towers and selective catalytic reduction systems, which primarily target sulfur oxides and nitrogen oxides, but lack effective onboard treatment methods for the major greenhouse gas, carbon dioxide.

[0003] Carbon dioxide capture is a technology for separating and enriching carbon dioxide from industrial flue gas. Mature processes mainly include solution absorption and solid adsorbent adsorption. Solution absorption has a large capacity but requires bulky equipment, consumes a lot of energy, and is easily affected by ship rolling; solid adsorbents (such as zeolites and molecular sieves) are more convenient for implementing compact pressure swing adsorption or temperature swing adsorption processes.

[0004] Methanol can be synthesized through multiple pathways, including the reaction of carbon dioxide and hydrogen, and the water-gas shift synthesis via the reaction of carbon monoxide and water vapor. The main reactions involved are shown below: The synthesis of methanol from carbon dioxide by hydrogenation:

[0005] Water-gas shift reaction:

[0006] During navigation, methanol is mainly produced by the water-gas shift reaction of CO in flue gas and water steam generated by boiler heating. This process consumes less electricity, which helps maintain the normal navigation of the ship. When docked, the ship connects to shore power and uses the CO2 collected during navigation to perform a carbon dioxide hydrogenation reaction to synthesize methanol, effectively solving the problem of reusing the collected CO2.

[0007] The reactors, catalysts, and processes for this technology are very mature, but its large scale and high energy consumption limit its applicability to ship platforms. Thermal management technology is a fundamental technology in engineering systems, involving the recovery and utilization of various types of waste heat (such as engine exhaust heat) through heat exchangers. By constructing high-temperature water, low-temperature water, and steam systems, energy can be utilized in a cascade manner to heat other equipment or drive power equipment.

[0008] In summary, ship exhaust gas treatment, carbon capture, methanol synthesis technology based on carbon monoxide and water vapor, methanol synthesis technology by carbon dioxide hydrogenation, and thermal management technology are all mature technologies. However, these technologies have long been independent of each other, and their inherent scale and operating conditions make it impossible for them to be directly and effectively integrated and applied on ships.

[0009] Current ship emissions reduction efforts primarily rely on using low-sulfur fuels, installing exhaust aftertreatment devices (such as scrubbers and SCR), or switching to alternative fuels (such as LNG and methanol). However, these methods either only address localized pollution issues or still rely on fossil fuels, leading to a "carbon lock-in" effect. While green methanol is considered a promising alternative fuel for ships, its onshore production faces challenges such as high costs, difficulty in obtaining carbon sources, and an underdeveloped supply chain. Furthermore, directly transferring large-scale land-based carbon capture and methanol synthesis facilities to ships presents insurmountable difficulties, including limited space, excessive energy consumption, and instability in the dynamic marine environment.

[0010] Therefore, existing technologies lack an integrated system that can operate efficiently within the limited space of a ship, achieve energy self-sufficiency, and directly convert emitted carbon into usable fuel. This patent is proposed against this technological backdrop.

[0011] This invention is dedicated to solving this systemic integration problem, and therefore has significant practical significance and innovative value. Summary of the Invention

[0012] To solve the above problems, the technical solution adopted by the present invention is: a methanol dual-fuel ship exhaust carbon capture and fuel regeneration system, comprising: Seawater desalination unit: used to output desalinated water at low temperature based on input seawater; Heat exchanger device: used to heat the desalinated water output from the seawater desalination device and output high-temperature water; Heavy oil combustion device: performs heavy oil combustion, outputs energy to power the ship's navigation, and exhausts the first combustion exhaust gas; Methanol combustion device: Combusts methanol to provide energy for the ship's navigation and exhausts secondary combustion exhaust gases; Exhaust gas treatment device: Based on the exhaust gas output from the heavy oil combustion device and the methanol combustion device, the device treats the exhaust gas to discharge CO gas and CO2 gas respectively. Methanol synthesis unit: Based on the CO and CO2 gases output from the tail gas treatment unit and the high-temperature water output from the heat exchanger unit, methanol is synthesized and then fed to the methanol combustion unit. Control system: Based on the ship's navigation status, the system controls the ship's navigation power and exhaust gas output to maximize carbon emission reduction benefits by adjusting the exhaust gas treatment device and the methanol synthesis device.

[0013] Further: the exhaust gas treatment device includes: Drying chamber: Drys the exhaust gas output from the heavy oil combustion device and the methanol combustion device, and outputs dried CO gas and CO2 gas; CO2 adsorption device: Based on the dried CO gas and CO2 gas output from the drying chamber, it adsorbs CO2 gas and outputs CO gas. CO2 desorption device: Desorbs CO2 gas adsorbed by the CO2 adsorption device and discharges CO2 gas; First compressor: compresses the CO2 gas discharged from the CO2 desorption module; CO2 storage tank: for storing compressed CO2 gas.

[0014] Furthermore, it also includes an electrical system to provide power to the seawater desalination unit, heat exchanger unit, heavy oil combustion unit, methanol combustion unit, exhaust gas treatment unit, and methanol synthesis unit.

[0015] Furthermore, it also includes a second compressor for compressing the methanol fuel output from the methanol synthesis unit.

[0016] Furthermore: the methanol combustion device includes: Methanol fuel tank: Used for storing methanol fuel; Methanol combustion chamber: used to burn the methanol fuel output from the methanol fuel tank; The heavy oil combustion device includes: Heavy oil combustion chamber: Used for storing heavy oil fuel; Heavy oil combustion chamber: used to burn the heavy oil fuel output from the heavy oil fuel tank.

[0017] Furthermore, the navigation status of the vessel includes when the vessel starts, when the vessel is in normal navigation, when the vessel is in adverse environment or maneuvering, when the vessel is in a low-load or anchored state, and when entering a high-load navigation phase.

[0018] Furthermore, the process of controlling the ship's propulsion and exhaust gas output to maximize carbon emission reduction benefits by adjusting the exhaust gas treatment device and the methanol synthesis device based on the ship's navigation status is as follows: When the ship starts, methanol in the methanol fuel tank is pumped to the methanol combustion chamber for combustion to provide power to the ship. The CO and CO2 mixed flue gas after combustion enters the drying chamber for drying. The dried flue gas enters the CO2 adsorption device to remove CO2. The separated CO enters the methanol synthesis device to synthesize methanol. The synthesized methanol is compressed by the compressor and then sent to the methanol fuel tank for storage. The solid adsorbent that has completed the adsorption of CO2 is sent to the CO2 desorption device. The desorbed CO2 is compressed by the compressor and then sent to the CO2 storage tank 6 for storage. At the same time, the seawater desalination device is turned on to desalinate the seawater. The desalinated seawater is stored in the low-temperature freshwater tank. The low-temperature freshwater in the low-temperature freshwater tank is cooled by the methanol combustion chamber through the heat exchanger. The heat exchanged by the heat exchanger heats the heavy oil fuel tank. The high-temperature freshwater after heat exchange is sent to the high-temperature freshwater tank for storage. The heated heavy oil is pumped to the heavy oil combustion chamber 8 for combustion. After the operation is stable, the methanol fuel is replaced to drive the main engine. When the ship is under normal navigation, the heavy oil combustion chamber operates to provide power for the ship's navigation, while the methanol combustion chamber is closed. The flue gas generated by the heavy oil combustion enters the drying chamber for drying, and the dried flue gas enters the CO2 adsorption device to remove CO2. The solid adsorbent that has completed CO2 adsorption is sent to the CO2 desorption device. The removed CO2 is compressed by the compressor and then sent to the CO2 storage tank for storage. The low-temperature water in the low-temperature fresh water tank is heated by the heat exchanger that cools the heavy oil combustion chamber and then sent to the methanol synthesis unit to react with the CO separated in the CO2 adsorption device to synthesize methanol. The synthesized methanol is compressed by the compressor and then sent to the methanol fuel tank for storage. When a ship is in a harsh environment or maneuvering, the operating power of the CO2 adsorption unit is reduced to decrease the load on the electrical system, the methanol synthesis unit is shut down, and the CO2 desorption unit is shut down, further reducing the ship's electrical load and avoiding a sudden loss of power to the entire ship, thus ensuring the safety of the ship's navigation. At the same time, the methanol combustion chamber starts working, together with the heavy oil combustion chamber, to provide power for the ship's navigation. When the ship is under low load or at anchor, the amount of engine exhaust gas is reduced. The operating intensity of the exhaust gas treatment device and the methanol synthesis device is adjusted to prioritize carbon capture efficiency and continuously accumulate methanol fuel. When a ship enters a high-load navigation phase, priority should be given to ensuring power output, and the exhaust gas treatment device should be operated at a reduced load to ensure the stability of the ship's power.

[0019] This invention provides a methanol dual-fuel ship exhaust carbon capture and fuel regeneration system, which addresses the emission reduction challenges of the shipping industry, the limitations of existing carbon capture and utilization technologies, and the bottlenecks in shipborne green fuel production.

[0020] 1. The shipborne carbon cycle and methanol fuel regeneration system provided by this invention achieves closed-loop integration of carbon capture and fuel synthesis on a ship platform. This system treats carbon oxides (CO, CO2) in engine exhaust as a resource, directly converting them into reusable methanol fuel, thus realizing a "carbon cycle" for ships from the source, significantly reducing greenhouse gas emissions, and providing a revolutionary technological path to solve the decarbonization problem of the shipping industry.

[0021] 2. This invention utilizes an innovative "combustion reaction device-drying chamber" pretreatment unit, which is specifically optimized for the high humidity characteristics of ship exhaust gas. This achieves exhaust gas drying, creating stable and efficient operating conditions for subsequent adsorption and synthesis processes, and solving the key bottleneck that makes it difficult to directly apply land-based technologies to shipboard applications.

[0022] 3. This invention designs a highly efficient self-consistent thermal management network. Through high and low temperature water circuits and steam power subsystems, the waste heat generated by combustion and synthesis reactions is recovered and utilized in stages to provide energy for adsorbent regeneration and reaction temperature maintenance. This greatly reduces the system's dependence on external energy sources and improves overall energy efficiency and economy.

[0023] 4. This system has good adaptability to different operating conditions. It can intelligently adjust the operating intensity of carbon capture and methanol synthesis according to the ship's navigation status (such as high-load navigation and low-load anchoring), which can ensure the ship's power demand and maximize carbon emission reduction benefits, thus achieving a balance between environmental protection and operational efficiency.

[0024] 5. This invention organically and systematically integrates multiple independent technical fields such as ship propulsion, exhaust gas treatment, carbon capture, chemical synthesis, and thermal management to form a compact and efficient shipboard energy system. This not only improves the environmental performance of ships but also brings potential fuel-saving benefits, complying with increasingly stringent international maritime environmental regulations.

[0025] In summary, the technical solution of this invention can transform ships from single emission sources into mobile carbon resource processing platforms, fundamentally reducing the carbon footprint of the shipping industry. This system boasts high integration, significant energy efficiency, and excellent safety, and has broad prospects for promotion and important practical significance in the fields of ship environmental protection technology and new energy applications. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the device.

[0028] Reference numerals: 1. Methanol fuel tank; 2. Heavy oil fuel tank; 3. Drying chamber; 4. CO2 adsorption device; 5. CO2 desorption device; 6. CO2 storage tank; 7. Methanol combustion chamber; 8. Heavy oil combustion chamber; 9. First compressor; 10. Second compressor; 11. First filter; 12. Methanol synthesis device; 13. Second filter; 14. First pump; 15. Second pump; 16. First heat exchanger; 17. High-temperature freshwater tank; 18. Second heat exchanger; 19. Third filter; 20. Low-temperature freshwater tank; 21. Seawater desalination module; 22. Third pump; 23. Fourth filter; 24. Fourth pump; 25. Third heat exchanger; 26. Fifth pump; 27. Fourth heat exchanger; 28. Sixth pump. Detailed Implementation

[0029] It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Figure 1 This is a schematic diagram of the device.

[0032] A methanol dual-fuel ship exhaust carbon capture and fuel regeneration system includes: Seawater desalination unit: used to output desalinated water at low temperature based on input seawater; Heat exchanger device: used to heat the desalinated water output from the seawater desalination device and output high-temperature water; Heavy oil combustion device: Based on the heat output from the heat exchanger, heavy oil is burned to output energy to power the ship's navigation and exhaust the first combustion exhaust gas; Methanol combustion device: Combusts methanol to provide energy for the ship's navigation and exhausts secondary combustion exhaust gases; Exhaust gas treatment device: Based on the exhaust gas output from the heavy oil combustion device and the methanol combustion device, the device treats the exhaust gas to discharge CO gas and CO2 gas respectively. Methanol synthesis unit 12: Based on the CO gas and CO2 gas output from the tail gas treatment unit and the high-temperature water output from the heat exchanger unit, methanol is synthesized and then fed to the methanol combustion unit. Control system: Based on the ship's navigation status, the control system adjusts the exhaust gas treatment device and the methanol synthesis device 12 to maximize the carbon emission reduction benefits of the ship's navigation power and exhaust gas output.

[0033] The exhaust gas treatment device includes: Drying chamber 3: Drys the exhaust gas output from the heavy oil combustion device and the methanol combustion device, and outputs dried CO gas and CO2 gas; CO2 adsorption device 4: Based on the dried CO gas and CO2 gas output from drying chamber 3, it adsorbs CO2 gas and outputs CO gas. CO2 desorption device 5: Desorbs CO2 gas adsorbed by CO2 adsorption device 4 and discharges CO2 gas; First compressor 9: Compresses the CO2 gas discharged from the CO2 desorption module; CO2 storage tank: for storing compressed CO2 gas.

[0034] Furthermore, the system also includes an electrical system that provides power to the seawater desalination unit, heat exchanger unit, heavy oil combustion unit, methanol combustion unit, exhaust gas treatment unit, and methanol synthesis unit 12.

[0035] Furthermore, the system also includes a second compressor 10 for compressing the methanol fuel output from the methanol synthesis unit 12.

[0036] The methanol combustion device includes: Methanol fuel tank 1: Used for storing methanol fuel; Methanol combustion chamber 7: used to burn the methanol fuel output from the methanol fuel tank 1; The heavy oil combustion device includes: Heavy oil combustion cabinet: used for storing methanol fuel; Methanol combustion chamber 7: used to burn the methanol fuel output from the methanol fuel tank 1.

[0037] Furthermore, the navigation status of the ship described in the system includes when the ship starts, when the ship is in normal navigation, when the ship is in adverse environment or maneuvering, when the ship is in a low load or anchored state, and when entering a high load navigation phase.

[0038] Example 1: A methanol dual-fuel ship exhaust carbon capture and fuel regeneration system includes: Seawater desalination unit: Used to output desalinated water at low temperature based on the input seawater. Heat exchanger device: used to heat the filtered desalinated water output from the seawater desalination device to output high-temperature water; Heavy oil combustion device: performs heavy oil combustion, outputs energy to power the ship's navigation, and exhausts the first combustion exhaust gas; Methanol combustion device: Combusts methanol to provide energy for the ship's navigation and exhausts secondary combustion exhaust gases; Exhaust gas treatment device: Based on the exhaust gas output from the heavy oil combustion device and the methanol combustion device, the device treats the exhaust gas to discharge CO gas and CO2 gas respectively. Methanol synthesis unit 12: Based on the CO gas and CO2 gas output from the tail gas treatment unit and the high-temperature water output from the heat exchanger unit, methanol is synthesized and then fed to the methanol combustion unit. Control system: Based on the ship's navigation status, the control system adjusts the exhaust gas treatment device and the methanol synthesis device 12 to maximize the carbon emission reduction benefits of the ship's navigation power and exhaust gas output.

[0039] The exhaust gas treatment device includes: Drying chamber 3: Drys the exhaust gas output from the heavy oil combustion device and the methanol combustion device, and outputs dried CO gas and CO2 gas; CO2 adsorption device 4: Based on the dried CO gas and CO2 gas output from drying chamber 3, it adsorbs CO2 gas and outputs CO gas. CO2 desorption device 5: Desorbs CO2 gas adsorbed by CO2 adsorption device 4 and discharges CO2 gas; First compressor 9: Compresses the CO2 gas discharged from the CO2 desorption module; CO2 storage tank: for storing compressed CO2 gas.

[0040] Furthermore, the system also includes an electrical system that provides power to the seawater desalination unit, heat exchanger unit, heavy oil combustion unit, methanol combustion unit, exhaust gas treatment unit, and methanol synthesis unit 12.

[0041] Furthermore, the system also includes a second compressor 10 for compressing the methanol fuel output from the methanol synthesis unit 12.

[0042] The methanol combustion device includes: Methanol fuel tank 1: Used for storing methanol fuel; Methanol combustion chamber 7: used to burn the methanol fuel output from the methanol fuel tank 1; A first filter 11 and a second pump 15 are sequentially installed between the methanol fuel tank 1 and the methanol combustion chamber 7. The heavy oil combustion device includes: Heavy oil combustion chamber: Used for storing heavy oil fuel; Heavy oil combustion chamber 8: used to burn the heavy oil fuel output from the heavy oil fuel tank 2.

[0043] A second filter 13 and a first pump 14 are sequentially arranged between the heavy oil combustion cabinet and the heavy oil combustion chamber 8; The heat exchanger assembly includes a first heat exchanger 16, a second heat exchanger 18, a third heat exchanger 25, and a fourth heat exchanger 27. The seawater desalination device includes: Fourth seawater filter 23: Used to filter the incoming seawater; Seawater desalination module 21: Desalinates the seawater filtered by the fourth seawater filter 23; Furthermore, it also includes a third pump 22 installed before the seawater desalination module 21 for introducing seawater; A fourth pump 24 is installed after the seawater desalination unit module to provide power for the output of the desalinated seawater. A low-temperature freshwater tank 20 is installed after the fourth pump 24 to store the desalinated seawater; The fifth pump 26 is installed after the low-temperature freshwater tank 20 to provide kinetic energy to the desalinated seawater output from the low-temperature freshwater tank 20. First heat exchanger 16: Used to heat the fresh water output from the fifth pump. Third heat exchanger 25: used to heat the fresh water output from the fifth pump; Second heat exchanger 18: used to heat the fresh water output from the fifth pump; Fourth heat exchanger 27: used to heat the fresh water output from the fifth pump; High-temperature freshwater tank 17: used to store the hot water heated by the first heat exchanger 16, the heated hot water output from the third heat exchanger 25, the heated hot water output from the second heat exchanger 18, and the hot water output from the fourth heat exchanger 27. Third filter 19: used to filter the hot water output from the high-temperature fresh water tank 17; Sixth pump 28: used to provide power for the output of hot water filtered by the third filter 19, and to supply the hot water to the methanol synthesis unit 12; The process of controlling the ship's navigation power and maximizing carbon emission reduction benefits by adjusting the exhaust gas treatment device and the methanol synthesis device 12 based on the ship's navigation status is as follows: When the ship starts, the methanol in the methanol fuel tank 1 is pumped to the methanol combustion chamber 7 for combustion to provide power to the ship. The CO and CO2 mixed flue gas after combustion enters the drying chamber 3 for drying. The dried flue gas enters the CO2 adsorption device 4 to remove CO2. The separated CO enters the methanol synthesis device 12 to synthesize methanol. The synthesized methanol is compressed by the compressor and then sent to the methanol fuel tank 1 for storage. The solid adsorbent that has completed the adsorption of CO2 is sent to the CO2 desorption device 5. The desorbed CO2 is compressed by the compressor and then sent to the CO2 storage tank 66 for storage. At the same time, the seawater desalination device is turned on to desalinate the seawater. The desalinated seawater is stored in the low-temperature freshwater tank 20. The low-temperature freshwater in the low-temperature freshwater tank 20 is cooled by the methanol combustion chamber 7 through the heat exchanger. The heat exchanged by the heat exchanger heats the heavy oil fuel tank 2. The high-temperature freshwater after heat exchange is sent to the high-temperature freshwater tank 17 for storage. The heated heavy oil is pumped to the heavy oil combustion chamber 8 for combustion. After the operation is stable, the methanol fuel is replaced to drive the main engine. When the ship is under normal navigation, the heavy oil combustion chamber 8 is working to provide power for the ship's navigation, the methanol combustion chamber 7 is closed, and the flue gas generated by the heavy oil combustion enters the drying chamber 3 for drying. The dried flue gas enters the CO2 adsorption device 4 to remove CO2. The solid adsorbent that has completed the adsorption of CO2 is sent to the CO2 desorption device 5. The CO2 that has been removed is compressed by the compressor and sent to the CO2 storage tank 6 for storage. The low-temperature water in the low-temperature fresh water tank 20 is heated by the heat exchanger that cools the heavy oil combustion chamber 8 and then sent to the methanol synthesis device 12 to react with the CO separated in the CO2 adsorption device 4 to synthesize methanol. The synthesized methanol is compressed by the compressor and sent to the methanol fuel tank 1 for storage. When the ship is in a harsh environment or maneuvering, the operating power of the CO2 adsorption device 4 is reduced to reduce the load on the power system, the methanol synthesis device 12 is shut down, and the CO2 desorption device 5 is shut down, further reducing the ship's power load and avoiding a sudden power outage to ensure the safety of the ship's navigation. At the same time, the methanol combustion chamber 7 starts to work, together with the heavy oil combustion chamber 8, to provide power for the ship's navigation. When the ship is under low load or at anchor, the amount of engine exhaust gas is reduced. The operating intensity of the exhaust gas treatment device and the methanol synthesis device 12 is adjusted to prioritize carbon capture efficiency and continuously accumulate methanol fuel. When a ship enters a high-load navigation phase, priority should be given to ensuring power output, and the exhaust gas treatment device should be operated at a reduced load to ensure the stability of the ship's power.

[0044] Considering the economic needs of ships during navigation, heavy oil is still used as fuel to power them. When the ship is sailing smoothly or in open water, methanol is not used as fuel to power it. When the ship is sailing in rough seas or maneuvering, methanol and heavy oil are used together as fuel to power the ship and ensure normal navigation. When the ship is sailing or in waters with special environmental requirements, heavy oil is not used as fuel to power it, and the power for navigation is provided by the combustion of methanol.

[0045] This system is particularly suitable for ocean-going container ships and tankers with high emission reduction requirements. It can effectively reduce ship carbon emissions, improve ship energy efficiency, and has significant environmental and safety benefits.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A methanol dual-fuel ship exhaust carbon capture and fuel regeneration system, characterized in that: include: Seawater desalination unit: used to output desalinated water at low temperature based on input seawater; Heat exchanger device: used to heat the desalinated water output from the seawater desalination device and output high-temperature water; Heavy oil combustion device: performs heavy oil combustion, outputs energy to power the ship's navigation, and exhausts the first combustion exhaust gas; Methanol combustion device: Combusts methanol to provide energy for the ship's navigation and exhausts secondary combustion exhaust gases; Exhaust gas treatment device: Based on the exhaust gas output from the heavy oil combustion device and the methanol combustion device, the device treats the exhaust gas to discharge CO gas and CO2 gas respectively. Methanol synthesis unit: Based on the CO and CO2 gases output from the tail gas treatment unit and the high-temperature water output from the heat exchanger unit, methanol is synthesized and then fed to the methanol combustion unit. Control system: Based on the ship's navigation status, the system controls the ship's navigation power and exhaust gas output to maximize carbon emission reduction benefits by adjusting the exhaust gas treatment device and the methanol synthesis device.

2. The methanol dual-fuel ship exhaust carbon capture and fuel regeneration system according to claim 1, characterized in that: The exhaust gas treatment device includes: Drying chamber: Drys the exhaust gas output from the heavy oil combustion device and the methanol combustion device, and outputs dried CO gas and CO2 gas; CO2 adsorption device: Based on the dried CO gas and CO2 gas output from the drying chamber, it adsorbs CO2 gas and outputs CO gas. CO2 desorption device: Desorbs CO2 gas adsorbed by the CO2 adsorption device and discharges CO2 gas; First compressor: compresses the CO2 gas discharged from the CO2 desorption module; CO2 storage tank: for storing compressed CO2 gas.

3. The methanol dual-fuel ship exhaust carbon capture and fuel regeneration system according to claim 1, characterized in that: It also includes the power system, which provides electricity for seawater desalination units, heat exchanger units, heavy oil combustion units, methanol combustion units, exhaust gas treatment units, and methanol synthesis units.

4. The methanol dual-fuel ship exhaust carbon capture and fuel regeneration system according to claim 1, characterized in that: It also includes a second compressor for compressing the methanol fuel output from the methanol synthesis unit.

5. The methanol dual-fuel ship exhaust carbon capture and fuel regeneration system according to claim 1, characterized in that: The methanol combustion device includes: Methanol fuel tank: Used for storing methanol fuel; Methanol combustion chamber: used to burn the methanol fuel output from the methanol fuel tank; The heavy oil combustion device includes: Heavy oil combustion chamber: Used for storing heavy oil fuel; Heavy oil combustion chamber: used to burn the heavy oil fuel output from the heavy oil fuel tank.

6. The methanol dual-fuel ship exhaust carbon capture and fuel regeneration system according to claim 1, characterized in that: The ship's navigation status includes when the ship starts, when the ship is in normal navigation, when the ship is in adverse environment or maneuvering, when the ship is in a low-load or anchored state, and when entering a high-load navigation phase.

7. The methanol dual-fuel ship exhaust carbon capture and fuel regeneration system according to claim 1, characterized in that: The process of controlling the ship's propulsion and exhaust gas output to maximize carbon emission reduction benefits based on the ship's navigation status by adjusting the exhaust gas treatment device and the methanol synthesis device is as follows: When the ship starts, methanol in the methanol fuel tank is pumped to the methanol combustion chamber for combustion to provide power to the ship. The CO and CO2 mixed flue gas after combustion enters the drying chamber for drying. The dried flue gas enters the CO2 adsorption device to remove CO2. The separated CO enters the methanol synthesis device to synthesize methanol. The synthesized methanol is compressed by the compressor and then sent to the methanol fuel tank for storage. The solid adsorbent that has completed the adsorption of CO2 is sent to the CO2 desorption device. The desorbed CO2 is compressed by the compressor and then sent to the CO2 storage tank 6 for storage. At the same time, the seawater desalination device is turned on to desalinate the seawater. The desalinated seawater is stored in the low-temperature freshwater tank. The low-temperature freshwater in the low-temperature freshwater tank is cooled by the methanol combustion chamber through the heat exchanger. The heat exchanged by the heat exchanger heats the heavy oil fuel tank. The high-temperature freshwater after heat exchange is sent to the high-temperature freshwater tank for storage. The heated heavy oil is pumped to the heavy oil combustion chamber 8 for combustion. After the operation is stable, the methanol fuel is replaced to drive the main engine. When the ship is under normal navigation, the heavy oil combustion chamber operates to provide power for the ship's navigation, while the methanol combustion chamber is closed. The flue gas generated by the heavy oil combustion enters the drying chamber for drying, and the dried flue gas enters the CO2 adsorption device to remove CO2. The solid adsorbent that has completed CO2 adsorption is sent to the CO2 desorption device. The removed CO2 is compressed by the compressor and then sent to the CO2 storage tank for storage. The low-temperature water in the low-temperature fresh water tank is heated by the heat exchanger that cools the heavy oil combustion chamber and then sent to the methanol synthesis unit to react with the CO separated in the CO2 adsorption device to synthesize methanol. The synthesized methanol is compressed by the compressor and then sent to the methanol fuel tank for storage. When a ship is in a harsh environment or maneuvering, the operating power of the CO2 adsorption unit is reduced to decrease the load on the electrical system, the methanol synthesis unit is shut down, and the CO2 desorption unit is shut down, further reducing the ship's electrical load and avoiding a sudden loss of power to the entire ship, thus ensuring the safety of the ship's navigation. At the same time, the methanol combustion chamber starts working, together with the heavy oil combustion chamber, to provide power for the ship's navigation. When the ship is under low load or at anchor, the amount of engine exhaust gas is reduced. The operating intensity of the exhaust gas treatment device and the methanol synthesis device is adjusted to prioritize carbon capture efficiency and continuously accumulate methanol fuel. When a ship enters a high-load navigation phase, priority should be given to ensuring power output, and the exhaust gas treatment device should be operated at a reduced load to ensure the stability of the ship's power.

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