Systems, methods and applications of compact marine carbon capture based on the coupling of methanol reforming and highly efficient membrane separation

Abstract

To provide a system, a method, and an application for carbon recovery system for compact type vessel based on connection between methanol reforming and high-efficiency membrane separation.SOLUTION: Propulsive power is supplied to a vessel by using a methanol aqueous solution as a raw material through steps such as reforming, separation of a reformate product, and hydrogen combustion, hydrogen fuel is manufactured through methanol steam reforming, anxiety about safety of high pressure hydrogen storage in a prior art is eliminated, efficient carbon recovery is carried out by storing separated carbon dioxide by compression and liquefying, heat is supplied for methanol steam reforming and preheating of the fuel by using excess heat of discharged flue gas, and comprehensive use of energy is achieved. Use of hydrogen energy is realized by a vessel without requiring storage and transportation of hydrogen, and a shipping industry contributes to green, low carbon, and sustainable development.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to the technical field of reducing carbon dioxide emissions from ships, and in particular to a system, method and application of compact marine carbon capture based on the combination of methanol reforming and highly efficient membrane separation. [Background technology]

[0002] In the increasingly serious background of global warming, carbon dioxide emitted from ships has become an important issue in the field of environmental protection. Therefore, the development of new ship fuel processing and carbon capture technologies is particularly important. Hydrogen as an ideal alternative fuel brings a new perspective to the use of clean energy and the problem of carbon dioxide emissions. However, the challenges of hydrogen storage and transportation still remain, and it is said that there are advantages to using methanol as a hydrogen fuel carrier. Based on this, methanol can produce hydrogen through a steam reforming reaction, but the carbon dioxide produced at the same time needs to be effectively separated and captured. Membrane separation technology is considered to be an ideal gas separation method due to its high efficiency and low energy consumption. Current ship fuel processing technology mainly focuses on the optimization of fossil fuels and rarely considers the coupling problem of carbon capture and fuel processing. Therefore, the development of a pre-combustion carbon capture system and method for ships that combines methanol steam reforming and highly efficient membrane separation technology is particularly important for improving the processing efficiency of ship fuel and reducing carbon emissions, and contributes to promoting the green, low-carbon and sustainable development of the shipping industry, but how to operate it specifically has required overcoming many practical technical difficulties.

[0003] Patent Document 1 discloses a methanol fuel supply system for ships. The system uses a fuel pump to send methanol fuel in a methanol fuel tank to a methanol reactor, and then the processed methanol fuel meets the combustion conditions and is then transported to the ship's engine to power the ship. The structure of the system is flexible and can be adjusted according to actual needs to meet the needs of different types of ships. However, the technology has some problems, such as methanol's low calorific value, difficulty in ignition, and still emits carbon during the combustion process.

[0004] Patent Document 2 discloses a comprehensive energy utilization system for hydrogen fuel-powered ships. The system uses compressed hydrogen as an energy source and generates electricity using hydrogen fuel cells and generators to propel the ship. The system realizes efficient energy utilization by making maximum use of the pressure energy of compressed hydrogen and the cold energy of the heat exchange process, and is clearly worthy of widespread use. However, this technology also has problems such as the high difficulty and high cost of storing and transporting hydrogen fuel, and the risk of leakage during storage and transportation, which raises safety concerns.

[0005] Furthermore, conventional post-combustion carbon capture technologies for ships usually require the use of a complete set of equipment, including capture devices, filters, storage facilities, etc. These equipment are generally large in size and take up a considerable amount of space on board the ship. Within the limited ship space, these equipment must be reasonably laid out with other major facilities of the ship (propulsion system, ship management system, etc.), which will undoubtedly increase the difficulty of design and assembly, and will also affect the ship's cargo capacity and passenger transport capacity.

[0006] The fastest way to solve these problems and reduce the high cost of storing and transporting hydrogen fuel and the space it takes up is to develop compact, safe, energy-efficient and low-cost storage and transportation technologies, but this requires overcoming many technical challenges and extensive experimentation and exploration.

[0007] Therefore, focusing on the shortcomings of existing technologies, in order to realize efficient carbon capture, we urgently need to research and develop a compact, cost-effective, stable and highly efficient application process for low-carbon alternative fuels. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] China Patent Application Publication No. 115306608 [Patent Document 2] China Patent Publication No. 113914940 Summary of the Invention [Problem to be solved by the invention]

[0009] In order to overcome the shortcomings and deficiencies of the prior art, the present invention provides a system, method and application of carbon capture for compact ships based on the combination of methanol reforming and highly efficient membrane separation. The present invention combines methanol steam reforming technology and membrane separation technology to efficiently generate hydrogen from methanol as ship fuel and to recover the generated carbon dioxide, thereby reducing greenhouse gas emissions from ships. The present invention produces hydrogen fuel through methanol steam reforming, avoids the use of dangerous high-pressure hydrogen, and uses a safe methanol aqueous solution, thereby resolving the safety concerns of high-pressure hydrogen storage in the prior art. At the same time, carbon capture is achieved by compressing and liquefying the carbon dioxide separated from the reforming product. The present invention utilizes the residual heat of the exhaust gas discharged to supply heat for methanol steam reforming and fuel preheating, thereby achieving comprehensive energy utilization. The present invention occupies a small area and is suitable for efficient carbon capture on ships in limited spaces. [Means for solving the problem]

[0010] In order to achieve the above object, the present invention employs the following technical means: A compact marine carbon capture system based on the combination of methanol reforming and highly efficient membrane separation, comprising: A compact reforming reaction device is used to produce hydrogen and carbon dioxide through a reforming reaction after mixing methanol and water. It has a compact design and is easy to install in the limited space inside the ship. It is equipped with a process for utilizing the residual heat from the ship's exhaust gas, and improves the energy utilization efficiency of the reforming reaction and the ability to utilize residual heat. A compact membrane separation device that is used to efficiently and quickly separate hydrogen and carbon dioxide produced by reforming, has a small size, efficient and fast separation performance, and can achieve low-cost and highly efficient H2 / CO2 gas separation by adopting cutting-edge separation membrane technology. A highly efficient, low energy consumption carbon dioxide compression and storage device that compresses and stores the separated carbon dioxide; The separated hydrogen is stored and transported to the ship's fuel system, and the hydrogen buffer tank has a compact design, is highly efficient, and can effectively store and transport hydrogen.

[0011] Preferably, the compact reforming reactor includes a methanol aqueous solution storage tank, a first preheater, an evaporator, a superheater, a reforming reactor, and a first condenser, which are sequentially connected to each other, and the first condenser is also connected to the first preheater, the evaporator, and the superheater, respectively, and residual heat of the reformed product can be supplied to the first preheater, the evaporator, and the superheater to realize cascade utilization of the residual heat; The compact membrane separation device includes a first mixing tank, a first gas-liquid separator, a membrane separator, a first compressor, a second condenser, a second gas-liquid separator, and a heater, which are sequentially connected to each other, the heater being connected to the first mixing tank, and the second gas-liquid separator being connected to a carbon dioxide compression and storage device; The high-efficiency, low-energy-consumption carbon dioxide compression and storage device includes a second compressor, a first heat exchanger, a third gas-liquid separator, a third compressor, a second heat exchanger, a fourth gas-liquid separator, and a third condenser, which are sequentially connected to each other, and the third condenser is connected to a carbon dioxide storage tank; One end of the hydrogen buffer tank is connected to the membrane separator and the other end is connected to a first flow divider, which is connected to a gas-fired boiler and an internal combustion engine, respectively. High-temperature flue gas generated from the gas-fired boiler and the internal combustion engine enters a second mixing tank and is mixed therewith to supply heat to drive the operation of the carbon dioxide compression and storage device. The second mixing tank is also connected to a first preheater, an evaporator, a superheater, and a reforming reactor, respectively. The flue gas residual heat can be supplied to the first preheater, the evaporator, the superheater, and the reforming reactor to realize cascaded utilization of the residual heat.

[0012] The present invention can reduce the energy consumption of the entire system by improving the thermal efficiency of the system and recovering the heat generated in the methanol-water steam reforming reaction to supply the residual heat for heating the aqueous methanol solution.

[0013] Preferably, the compact reforming reactor has a membrane and a catalyst unit inside, the membrane is used to fix the catalyst and distribute the reactants uniformly, the catalyst unit includes a catalytic reforming zone, the outer periphery of the catalytic reforming zone is a heating zone, the heating zone receives high-temperature flue gas to supply the required heat energy to the catalytic reforming zone, the flow path design enhances the rapid heat transfer, and the precise design and control of the thermal fluid flow rate ensures that the catalyst is in the optimum reaction temperature zone.

[0014] Preferably, the high-efficiency, low-energy-consumption carbon dioxide compression and storage device further includes an absorber, a third heat exchanger, a solution pump, a reboiler, a generator, an absorption liquid recovery device, a fourth heat exchanger and a throttle valve, wherein the absorber is used for absorbing refrigerant from the refrigeration cycle pipeline, the third heat exchanger is used for adjusting the temperature of the entire device, the solution pump is used for transporting liquid, the reboiler is used for heating the refrigerant, the generator is used for generating the required refrigerant, the absorption liquid recovery device is used for collecting and recovering the absorption liquid, the fourth heat exchanger is used for controlling the heat exchange of the device, and the throttle valve is used for adjusting and controlling the flowing refrigerant.

[0015] Preferably, the volume ratio of methanol to water in the methanol aqueous solution storage tank is 6: 4. The methanol aqueous solution in the methanol aqueous solution storage tank exists in a liquid state under normal temperature and pressure, which greatly reduces the risk of high pressure leakage, and since the volume ratio of methanol to water is 6 / 4, the mass hydrogen density of the methanol aqueous solution can reach 12 wt%, and the storage system can efficiently store and supply hydrogen fuel.

[0016] The present invention also provides a marine pre-combustion carbon capture method based on methanol steam reforming and membrane separation technology, which includes the following steps: (1) Production of hydrogen and carbon dioxide using methanol steam reforming reaction: Methanol and water are mixed and subjected to a steam reforming reaction via a catalyst at a temperature of 180°C to 280°C and a pressure of 0.1MPa to 3MPa to produce hydrogen and carbon dioxide. (2) Separation of the produced hydrogen and carbon dioxide using membrane separation technology: Hydrogen and carbon dioxide are separated through a membrane material with selectivity and permeability. (3) Realization of carbon capture by compressing and storing the separated carbon dioxide: Compressing the carbon dioxide with a purity of 98% or more generated during the membrane separation process and converting it into liquid carbon dioxide, and then storing the compressed carbon dioxide in a high-pressure storage tank for future carbon dioxide containment or other carbon dioxide uses; and (4) Transporting the separated hydrogen to the ship's fuel system and using it as fuel: The separated hydrogen will be transported through a transport pipe to the ship's fuel system and used as clean fuel in the ship's engine system, thereby achieving low-carbon and zero-emission operation of the ship.

[0017] Preferably, the catalyst in step (1) is a copper-zinc-aluminum catalyst doped with cerium and niobium, which is prepared by mixing, drying and roasting 30% to 45% CuO, 25% to 45% ZnO, 10% to 20% Al2O3, 0.1% to 3.5% CeO2 and 0.1% to 2.5% Nb2O5 in mass fractions, and doping with cerium and niobium by coprecipitation to improve catalytic activity and stability;

[0018] The membrane material in step (2) is a MOF modified gas separation membrane, and the MOF modified gas separation membrane is prepared through the following steps: (a) adding the activated MOF powder to acetone and dispersing the MOF in acetone by water bath sonication to form a MOF ink, where the concentration of MOF in acetone is 5 g / L-30 g / L; (b) Add polyvinylidene fluoride to water and stir to form a viscous membrane solution with a concentration of 6 wt% to 10 wt%; (c) Add the film liquid to the MOF ink, and continue ultrasonic treatment to remove the acetone in the mixed solution by volatilization to obtain a viscous casting liquid; (d) Pour the casting liquid onto a glass plate to form a film of 200 μm to 300 μm, then place in an oven at 60 ° C to 80 ° C to preheat it, and remove the film after the water has completely evaporated. (e) Place the membrane from step (d) in a glass ring on a Teflon plate, add the pre-prepared 3 wt% polyimide solution, then place the Teflon plate in an oven at 60-90 °C to remove the polyimide and obtain a MOF-modified gas separation membrane (a gas separation membrane with high MOF content).

[0019] The reforming reaction temperature is preferably 180°C to 280°C.

[0020] Preferably, an external water production system is provided to convert seawater into fresh water via reverse osmosis so that the seawater can be used as a water source for the methanol steam reforming hydrogen production reaction, and the operating temperature of each device in the external water production system is kept at room temperature and the pressure is kept at 1 atm.

[0021] The present invention also provides an application of a compact marine carbon capture system based on the combination of methanol reforming and highly efficient membrane separation, that is, the operation of the compact marine pre-combustion carbon capture system includes the following steps: (1) First, the battery must be pre-charged to provide the required power throughout the entire process; (2) controlling the battery pack to turn on the power and supply power from the battery pack to the methanol reforming hydrogen production module to start the methanol reforming hydrogen production process; (3) After the methanol steam reforming hydrogen production module reaches the set temperature, hydrogen is quickly released and supplied to the hydrogen buffer tank, which is equipped with a pressure detection device, a temperature detection device, and a density detection device to ensure the safety and efficiency of operation. After that, the internal combustion engine is started to supply kinetic energy to the drive system. (4) After the methanol steam reforming hydrogen production module starts to normally output hydrogen, the residual heat of the exhaust gas from the internal combustion engine can be used to supply heat to the reforming reaction module, thereby cutting off the output of the battery module (during this process, the battery module is regarded as a backup power source and is on standby at any time); (5) The central display console automatically adjusts the hydrogen filling and discharging mass of the hydrogen buffer tank and the output of the internal combustion engine according to the real-time situation of the ship, and when there is a surplus in the export power of the internal combustion engine, the system starts charging the battery modules; Including, In the above process, an intelligent control method is used to perform multivariate control (multiparameter control) of a compact marine carbon capture system based on the combination of methanol reforming and highly efficient membrane separation.

[0022] Due to the need to adjust the ship's operating load and fuel supply at any time during ship startup and in a complex navigation environment, the requirements for stability, adjustability and economy of the compact ship carbon capture system are further increased. The steps for constructing an intelligent control method are as follows: S1: Install online monitoring equipment for core equipment of the system, such as the hydrogen buffer tank, methanol reformer, membrane separator, and ship engine. Combine the design parameters of the core equipment of the system with navigation know-how to build a data middle office that includes important parameters of methanol reforming, highly efficient membrane separation of reformed products, and ship power generation processes. This will enable data collection, governance, analysis and mining, giving the system the power to control intelligently. S2: Study the coupling relationship between the compact reforming reactor, compact membrane separation device, ship power generation, high-efficiency and low-energy consumption carbon dioxide compression and storage device and hydrogen buffer tank, etc., identify the key factors that affect the low-energy consumption and stable operation of the above devices, and build a knowledge and data fusion-driven key parameter model for compact ship carbon capture control;

[0023] The parameters of the key parameter model of the knowledge and data fusion driven compact marine carbon capture control include carbon capture efficiency η CO2 , the operating temperature of the superheater T s , methanol water vapor flow rate V m , the operating temperature of the reforming reaction T m , reforming reactor operating pressure P m , gas flow velocity inside the membrane V s , engine output W e , the ship's exhaust gas temperature T T , H2 recovery amount after membrane separation L n and the formula is expressed as follows:

[0024]

number

[0025] S3: Further study the key indicators of efficiency-energy consumption-material consumption under operating conditions, and establish an energy flow and material flow cost evaluation model for a compact marine carbon capture system based on the combination of methanol reforming and highly efficient membrane separation. The equations for the energy flow cost E and material flow cost C evaluation model are expressed as follows:

[0026] E=E f +E P +E h +E v +E h1 +E r +E s +E c +E h2 +E a

[0027] Energy consumption: Booster fan power consumption E f , Power consumption of transfer pump E p、 Power consumption of the first preheater E h , evaporator power consumption E v、 Superheater power consumption E h1 , the power consumption of the reforming reactor E r , power consumption of membrane separator E s , power consumption of the first compressor E c , Heater power consumption E h2 , power consumption of air transport fan Ea ,

[0028] C=C m +C w +C c +C s +C s +C l

[0029] Material consumption: Methanol C m , water C w , catalyst C c , Membrane Assembly C s , refrigerant C l ,

[0030] S4: Using the established energy consumption-material consumption comprehensive cost evaluation model of methanol steam reforming combined with membrane separation, carry out efficiency-energy consumption-material consumption analysis under the fluctuation of load / operating conditions, and find the optimal parameter combination of cost, to build a global optimization parameter model of the system under the fluctuation of load / operating conditions for efficiency-energy consumption-material consumption analysis, and find the global optimization parameters of the system to accurately evaluate the dynamic operating costs of all flows of the compact reforming reactor, compact membrane separation device, and ship power generation under different operating conditions in real time, comprehensively considering the stability and economic constraints of each device, and solving them through intelligent optimization algorithms including particle swarm and ant colony to obtain the optimal parameter combination of the energy consumption-material consumption comprehensive cost;

[0031] The energy and material consumption of each device is quantified by cost, and the complex physical problem is transformed into an economic problem. In the specific operation, the energy consumption (such as the power consumption of the booster fan, the power consumption of the transfer pump, etc.) and material consumption (such as methanol, water, catalyst, etc.) of each device are taken as variables, and the overall cost is taken as the optimization target. An overall cost function based on energy and material consumption is constructed, and then the function is solved by intelligent optimization algorithms such as particle swarm and ant colony, and the combination of parameters that minimizes the overall cost is found, thereby constructing a global optimization parameter model of the system under the variation of load / operating conditions for efficiency-energy consumption-material consumption analysis;

[0032] Cost-performance optimization problem of a coupled system of methanol steam reforming and product membrane separation: minE=E f +E P +E h +E v +E h1 +E r +E s +E c +E h2 +E a minC=Cm +C w +C c +C s +C s +C l

number

[0033] S5: After obtaining the optimal parameter combination of the total cost of energy consumption and material consumption, construct an optimization objective function and solve the optimization problem with a multi-objective optimization algorithm to further realize the strategy formulation. The strategy implements collaborative optimization among multiple devices such as reforming reactor, compact membrane separator and ship power generation under the multi-objective constraint of energy consumption-material consumption-carbon emission, and provides real-time guidance for flexible adjustment of key parameters of the core devices of the system under the fluctuation of load / operating conditions to further reduce material consumption and energy consumption.

[0034] Based on the above optimization parameter model, a coordinated optimization strategy between multiple devices, namely, a reforming reactor, a compact membrane separation device and a ship power generation device, is established under the multi-objective goal of energy consumption-material consumption-carbon emission. In this strategy, a multi-objective optimization model is established with energy consumption, material consumption and carbon emission as optimization goals. This model requires finding a parameter combination that optimizes the overall performance of these three goals on the premise of satisfying the operation requirements and environmental constraints of the device. After finding the optimal parameter combination, it is solved by an intelligent optimization algorithm and combined with the actual operating conditions to provide real-time guidance for flexible adjustment of the key parameters of the core devices of the system under load fluctuations, and provides real-time guidance for flexible adjustment of the key parameters of the core devices of the system under load / operating condition fluctuations, thereby further reducing material consumption and energy consumption.

[0035] The present invention uses aqueous methanol solution as raw material, and generates hydrogen through reforming reaction in a methanol reformer, and then converts the hydrogen into power in a hydrogen internal combustion engine, thereby realizing the direct utilization of hydrogen energy. This innovative methanol hydrogen production system enables ships to directly utilize hydrogen energy without filling hydrogen, effectively solving the problem of hydrogen filling faced in the development of traditional hydrogen fuel cells. In addition, the present invention enables ships to be powered by hydrogen, effectively avoiding the situation where the carbon emissions of ships do not meet environmental protection standards. Through a series of optimization measures, the present invention shows remarkable benefits in many aspects, such as reducing greenhouse gas emissions, reducing dependence on fossil fuels, capturing carbon dioxide, and improving the energy utilization efficiency and cruising range of ships. This not only contributes to promoting the green, low-carbon and sustainable development of the shipping industry, but also provides practical technical measures for the global response to climate change. Effect of the Invention

[0036] Compared with the prior art, the present invention has the following advantageous effects:

[0037] (1) The present invention uses a compact reforming reactor, a compact membrane separation device, a highly efficient and energy-efficient carbon dioxide compression storage device, and a hydrogen buffer tank to mix methanol and water and carry out a steam reforming reaction to produce hydrogen fuel. Compared with the direct loading of high-pressure hydrogen fuel, the need for a high-pressure large-capacity hydrogen storage tank for storing hydrogen is eliminated, which obviously improves the safety of the ship. By loading safe methanol water, more hydrogen can be carried for the same mass, so the present invention is particularly suitable for large ships sailing long distances. The system of the present invention only occupies 1 / 4 of the post-treatment facility, which is suitable for efficient carbon recovery on ships in limited space, and the integrated arrangement of the microchannel high-efficiency heat exchange and multifunctional catalyst can be used to realize the ultra-compact reactor, while the reforming product separation membrane uses a multi-stage and multi-channel arrangement to realize the compact design of the membrane separation device. In addition, the ultra-small methanol steam reforming reactor and compact membrane separation device adopt a compact coupled integrated design to easily prepare marine power fuel in a limited space. At the same time, the amount of treated gas used by the system for pre-combustion membrane separation carbon capture is only 5% of the amount of treated gas used by traditional post-combustion exhaust gas carbon capture, further reducing the space required by the system, and the investment cost for installing the system is about 1 / 4 of that of traditional post-combustion carbon capture systems.

[0038] (2) Based on the idea of ​​recovering carbon from the source before combustion, the present invention adopts a methanol steam reforming method combined with membrane separation, and uses a reforming reactor equipped with microchannel high-efficiency heat exchange and multifunctional catalyst to realize high-efficiency and low-energy consumption conversion of methanol steam and efficient utilization of exhaust gas residual heat. The composition of the reforming product gas is simple (mainly CO2 and H2). The use of MOF reforming gas separation membrane assembly can realize efficient preparation of hydrogen fuel and low-energy consumption and efficient recovery of CO2. In addition, the reforming product is efficiently separated and carbon is recovered at low cost, and the carbon recovery efficiency reaches 98%. Compared with the traditional post-treatment decarbonization system, it can be improved by more than 45%, and at the same time, the reforming product does not generate ship exhaust gas pollutants such as nitrogen oxides, sulfur oxides, and particulate matter, and there is no need to install exhaust gas purification systems such as desulfurization, denitrification, and dust removal on the ship, which further reduces the investment cost and the layout space of the ship's engine room.

[0039] (3) The present invention uses methanol steam reforming to produce hydrogen fuel as the power source for ships, which has a calorific value 12% higher than that of direct combustion of methanol, and 75% of the residual heat of the engine exhaust gas is recovered and used in the methanol steam reformer, thereby realizing comprehensive utilization of energy, effectively improving propulsion efficiency, saving energy consumption, and reducing the operation cost of the ship. To save energy consumption, the present invention further uses a reforming reactor equipped with a microchannel high-efficiency heat exchange and a multi-functional low-temperature catalyst (compared to the operating temperature of the conventional catalyst, the operating temperature is reduced by more than 20°C), reducing the input of external heat source and reducing reforming energy consumption, and further combining it with a compact membrane separation device that does not require external heat supply to realize carbon recovery with low energy consumption.

[0040] (4) Due to the need to adjust the ship's operating load and fuel supply at any time during ship startup and in a complex navigation environment, there are increasing requirements for the stability, adjustability and economy of the compact ship carbon capture system. The present invention deeply integrates advanced control of core devices, accurate prediction in advance of key parameters, navigation experience and knowledge, and comprehensively considers the coupling between the compact reforming reactor, compact membrane separation device, high-efficiency and low energy consumption carbon dioxide compression and storage device and hydrogen buffer tank, as well as carbon emissions and economic constraints. Through advance prediction and intelligent control of key parameters of the knowledge and data fusion-driven compact ship carbon capture system, it is possible to reduce material consumption and energy consumption while improving the adjustability of the system under changing load / operating conditions. [Brief description of the drawings]

[0041] [Figure 1] FIG. 1 is a schematic diagram of the process route of a compact marine pre-combustion carbon capture system of methanol steam reforming combined with highly efficient membrane separation technology of product CO2 of the present invention. [Diagram 2] FIG. 2 is a schematic diagram of the operation flow of the compact reforming reactor of the present invention. [Diagram 3] FIG. 1 is a schematic diagram of the working principle of compact gas membrane separation of the present invention. [Figure 4] FIG. 1 is a schematic diagram of the highly efficient and low energy consumption CO2 compression and liquefaction flow of the present invention. [Diagram 5] FIG. 1 is a schematic diagram of the carbon emission reduction effect of different processes. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0042] The technical means of the present invention will be described in more detail through the following examples, but these examples are for the purpose of illustrating the present invention and are not intended to limit the present invention. All other examples obtained by those skilled in the art based on the examples in this application without any creative activity are within the scope of protection of this application. EXAMPLES

[0043] Referring to FIG. 1, a compact marine carbon capture system based on the combination of methanol reforming and highly efficient membrane separation, which includes a compact reforming reactor, a compact membrane separation device, a highly efficient and low energy consumption carbon dioxide compression and storage device, and a hydrogen buffer tank, The compact reforming reactor is used to mix methanol and water and then carry out a steam reforming reaction to produce hydrogen and carbon dioxide. The compact membrane separation device separates the produced hydrogen and carbon dioxide, The highly efficient and low energy consumption carbon dioxide compression and storage device compresses and stores the separated carbon dioxide. Hydrogen buffer tanks are used to store and transport separated hydrogen to the ship's fuel system.

[0044] The compact reforming reactor includes a methanol aqueous solution storage tank 1, a transfer pump 2, a first preheater 3, an evaporator 4, a superheater 5, a reforming reactor 6, and a first condenser 7, which are connected in sequence. The first condenser 7 is also connected to the first preheater 3, the evaporator 4, and the superheater 5, respectively. The compact membrane separation apparatus includes a first mixing tank 8, a first gas-liquid separator 9, a membrane separator 10, a first compressor 13, a second condenser 14, a second gas-liquid separator 15, and a heater 16, which are connected in series. The heater 16 is connected to the first mixing tank 8, and the second gas-liquid separator 15 is connected to a carbon dioxide compression and storage apparatus. The compact membrane separator 10 is also connected to a first diverter 12, and a hydrogen buffer tank 11 is provided between the compact membrane separator 10 and the first diverter 12. In order to ensure the safety and efficiency of operation, a pressure detector, a temperature detector, and a density detector are installed in the hydrogen buffer tank. The first diverter 12 is connected to a gas-fired boiler 17 and an internal combustion engine 18, respectively. Air enters the gas-fired boiler 17 and the internal combustion engine 18 through a second diverter 19. High-temperature flue gas generated from the gas-fired boiler 17 and the internal combustion engine 18 enters a second mixing tank 20 and is mixed to supply heat to drive the operation of the carbon dioxide compression and storage device. The flue gas residual heat 21 is supplied to the first preheater 3, the evaporator 4, the superheater 5, and the reforming reactor 6. The residual heat 22 of the reforming product is supplied to the first preheater 3, the evaporator 4, and the superheater 5, thereby realizing cascade utilization of the residual heat.

[0045] The methanol aqueous solution in the methanol aqueous solution storage tank 1 is sent to the first preheater 3 via the transfer pump 2, where it is preheated, and the heated mixture enters the evaporator 4 for evaporation, then passes through the superheater 5 for superheating, and the superheated gas enters the reforming reactor 6, where the reforming reaction occurs, and the product generated by the reforming reaction enters the first condenser 7 for condensation, and then enters the first mixing tank 8. The mixture in the first mixing tank 8 is sent to the first gas-liquid separator 9, where gas-liquid separation is performed, and the separated gas enters the membrane separator 10 for further separation, and the membrane separator 10 separates CO2 and H2. The CO2 enters the first compressor 13 and is compressed, then enters the second condenser 14 and is condensed. The condensed gas is sent to the second gas-liquid separator 15, where it is further separated. The liquid rich in methanol is sent to the heater 16 to be heated and then enters the first mixing tank 8, and the gas CO2 separated in the second gas-liquid separator 15 enters the carbon dioxide compression and storage device. The H2 in the membrane separation product is stored in the hydrogen buffer tank 11, and the H2 in the hydrogen buffer tank 11 passes through the first flow divider 12, with a portion of it being used as fuel for the hydrogen internal combustion engine 18, and the other portion entering the gas-fired boiler 17 for combustion. The air is divided through the air flow divider 19, with a portion entering the hydrogen internal combustion engine 18 and the other portion entering the gas-fired boiler 17, and the high-temperature flue gas generated from the internal combustion engine and the gas-fired boiler entering the second mixing tank 20 and mixing, supplying heat to drive the operation of the carbon dioxide compression and storage device. The flue gas residual heat 21 is supplied to the first preheater 3, the evaporator 4, the superheater 5, and the reforming reactor 6, and the residual heat 22 of the reforming product is supplied to the first preheater 3, the evaporator 4, and the superheater 5, thereby realizing cascaded utilization of the residual heat.

[0046] The present invention efficiently uses methanol as fuel to produce hydrogen, recovers the carbon dioxide generated to reduce greenhouse gas emissions from ships, and realizes the recovery and utilization of high-temperature flue gas and residual heat from reforming products through the principle of heat cascade utilization.

[0047] The present invention can reduce the energy consumption of the entire system by improving the thermal efficiency of the system and recovering the heat generated in the methanol-water steam reforming reaction to supply the residual heat for heating the aqueous methanol solution.

[0048] Referring to FIG. 2, the compact reforming reactor has a membrane 2-5 and a catalyst unit 2-6 inside. The membrane 2-5 is used to fix the catalyst and uniformly distribute the reactants. The catalyst unit 2-6 includes a catalytic reforming region 2-7. The outer periphery of the catalytic reforming region 2-7 is a heating region 2-8. The heating region 2-8 receives high-temperature flue gas to supply the necessary thermal energy to the catalytic reforming region 2-7.

[0049] Figure 2 shows the operation flow and design of the compact reforming reactor, which has a cylindrical housing with an inlet pipe at the front end for feeding the raw material and an outlet pipe at the rear end for discharging the product. At the same time, a passage connected to the heat supply inlet pipe and the heat supply outlet pipe is provided inside the housing to realize the input and output of heat. In the reactor, methanol (CH3OH) and water (H2O) are introduced into the reactor through the raw material inlet 2-1 as the initial reactants. The high-temperature flue gas generated by combustion is injected into the combustion chamber through the heat source inlet 2-9 as the heat source. The reforming reactants are evaporated to a gaseous state in the reactor evaporation chamber 2-3 and then transported uniformly into the reactor through the feed system 2-4. Inside the reactor, two important parts are involved: the membrane 2-5 and the catalyst unit 2-6, which jointly complete the reforming reaction process. The main role of the membrane 2-5 is to fix the catalyst and distribute the reactants evenly so that the reactants can contact the catalytic unit 2-6 more effectively. The inside of the catalytic unit 2-6 includes the catalytic reforming area 2-7, where methanol and water undergo a reforming reaction under the action of the catalyst. The outer periphery of the catalytic reforming area 2-7 is the heating area 2-8. The heating area provides the necessary heat energy for the catalytic reforming area 2-7 by receiving the high-temperature flue gas. The low-temperature flue gas is discharged from the reactor through the low-temperature flue gas outlet 2-2. After the reforming reaction is completed, the reformed products CO2 and H2 are discharged from the reactor through the reformed product outlet 2-10 for further utilization or treatment.

[0050] Referring to FIG. 3, FIG. 3 shows the working principle and process of the compact gas membrane separator. When the gas membrane separation process is started, a mixed gas of CO2 and H2 is introduced into the gas membrane separator. The separator achieves gas separation by using a special membrane technology designed to pass different gases at different speeds. When the mixed gas passes through the membrane, the permeability of H2 is high and the permeability of CO2 is low. Therefore, H2 mainly passes through the membrane and flows out to form H2 separated gas, and CO2 is concentrated on one side of the membrane to form CO2 concentrated gas. In this way, the gas membrane separator separates the mixed gas of CO2 and H2 to obtain higher purity H2 gas (purity above 98%) and concentrated CO2 gas.

[0051] In the structural design of the reforming reactor and the compact membrane separator shown in Figures 2 and 3, the highly efficient microchannel heat exchanger and the multi-functional catalyst are integrated to realize the ultra-compact reactor, and at the same time, the reforming product separation membrane is arranged in a multi-stage, multi-channel format to realize the compact design of the membrane separation device. Furthermore, the ultra-compact methanol steam reforming reactor and the compact membrane separation device are integrated in a compact design to realize the easy preparation of marine power fuel in a limited space.

[0052] 4, the high-efficiency, low-energy-consumption carbon dioxide compression and storage apparatus includes a second compressor 4-1, a first heat exchanger 4-2, a third gas-liquid separator 4-3, a third compressor 4-4, a second heat exchanger 4-5, a fourth gas-liquid separator 4-6, and a third condenser 4-7, which are connected in series, and the third condenser 4-7 is connected to a carbon dioxide storage tank 4-8. The carbon dioxide compression and storage apparatus further includes an absorber 4-9, a third heat exchanger 4-10, a solution pump 4-11, a reboiler 4-12, a generator 4-13, an absorbent recovery unit 4-14, a fourth heat exchanger 4-15, and a throttle valve 4-16.

[0053] FIG. 4 shows a highly efficient and low energy consumption CO2 carbon dioxide compression and storage device, which compresses and stores the separated carbon dioxide, and converts gaseous carbon dioxide into liquid carbon dioxide. The components and process of the diagram are described in detail below. The gaseous carbon dioxide in the device is introduced into the second compressor 4-1, and then the compressed gas enters the first heat exchanger 4-2 to be cooled by seawater spray, and then enters the third gas-liquid separator 4-3 for initial gas-liquid separation, after which the gaseous carbon dioxide enters the third compressor 4-4 for secondary compression, then passes through the second heat exchanger 4-5 to be cooled by seawater spray, and again enters the fourth gas-liquid separator 4-6 for further gas-liquid separation, during which part of the carbon dioxide is converted into liquid. The gas-liquid mixed carbon dioxide enters the third condenser 4-7, where the carbon dioxide is cooled to room temperature and completely liquefied. The liquid carbon dioxide obtained in this process can be stored in the carbon dioxide storage tank 4-8 ​​or transported to other places for use. The absorber 4-9 absorbs the refrigerant from the refrigeration cycle pipeline, the third heat exchanger 4-10 is used for adjusting the temperature of the whole system, and the solution pump 4-11 is used for transferring the liquid. The reboiler 4-12 is used for heating the refrigerant. The high-temperature steam 4-17 and the low-temperature water 4-18 are used for driving and cooling the equipment and also help to maintain the operation of the whole system. The generator 4-13 generates the required refrigerant, the absorption liquid recovery unit 4-14 collects and reuses the absorption liquid, the fourth heat exchanger 4-15 is used for controlling the heat exchange of the system, and the throttle valve 4-16 is used for adjusting and controlling the flowing refrigerant. The carbon dioxide compression and storage device used in the present invention can effectively convert gaseous carbon dioxide into a liquid state, making it easy to store and transport.

[0054] The multi-stage compression method of the present invention can effectively reduce the energy consumption during the compression process and improve the compression efficiency of carbon dioxide. In addition, in order to further improve the thermal efficiency of the system, the heat generated in the methanol-water steam reforming reaction is recovered and used as residual heat to heat the methanol water solution, thereby reducing the energy consumption of the entire system. The volume ratio of methanol to water in the methanol water solution storage tank is 6:4. The methanol water solution in the methanol water solution storage tank exists in a liquid state under normal temperature and pressure, which greatly reduces the risk of high-pressure leakage, and the methanol water in the methanol water solution storage tank passes through the methanol reforming hydrogen production device to generate hydrogen-rich gas. This hydrogen-rich gas is introduced into the internal combustion engine to provide kinetic energy for driving the ship's operation. Importantly, since the volume ratio of methanol to water is 6 / 4, the mass hydrogen density of the methanol water can reach 12 wt%, and the storage system can efficiently store and supply hydrogen fuel.

[0055] A method for pre-combustion carbon capture for ships using the above system includes the following steps: (1) Production of hydrogen and carbon dioxide using methanol steam reforming reaction: Methanol and water are mixed in a volume ratio of 6:4, and the mixed steam is subjected to a steam reforming reaction at a reaction temperature of 180 to 280°C and a reaction pressure of 0.1 to 3 MPa through a copper-zinc-aluminum catalyst doped with cerium and niobium to produce hydrogen and carbon dioxide (the catalyst is prepared by mixing, drying, and roasting 40% CuO, 40% ZnO, 15% Al2O3, 3% CeO2, and 2% Nb2O5 by mass fraction); (2) Separation of the produced hydrogen and carbon dioxide using membrane separation technology: A process in which hydrogen and carbon dioxide are separated through a membrane material with selectivity and permeability; The membrane material is a MOF modified gas separation membrane, and the MOF modified gas separation membrane is prepared through the following steps: (a) adding the activated MOF powder to acetone and dispersing the MOF in acetone by water bath sonication to form a MOF ink, where the concentration of MOF in acetone is 5 g / L-30 g / L; (b) Polyvinylidene fluoride is added to water and stirred to form a viscous membrane solution with a concentration of 6 wt% to 10 wt%; (c) Add the film liquid to the MOF ink, and continue ultrasonic treatment to remove the acetone in the mixed solution by volatilization, to obtain a viscous casting liquid; (d) Pour the casting liquid onto a glass plate to form a film of 200 μm to 300 μm, then place in an oven at 60 ° C to 80 ° C to preheat it, and remove the film after the water has completely evaporated. (e) placing the membrane from step (d) in a glass ring on a Teflon plate, adding the pre-prepared 3 wt% polyimide solution, then placing the Teflon plate in an oven at 60-90°C to remove the polyimide, and obtaining a MOF-modified gas separation membrane; (3) Carbon capture by compression and storage of separated carbon dioxide: Compressing the high-purity carbon dioxide (98% or more purity) generated during the membrane separation process and converting it into liquid carbon dioxide, which is then stored in a high-pressure storage tank for future carbon dioxide containment or other carbon dioxide uses; and (4) Transporting the separated hydrogen to the ship’s fuel system and using it as fuel: The process involves transporting the separated hydrogen through a transport pipe to the ship’s fuel system and using the hydrogen as clean fuel in the ship’s internal combustion engine system, thereby achieving low-carbon and zero-emission operation of the ship.

[0056] The present invention is equipped with an external freshwater production system to convert seawater into freshwater through reverse osmosis equipment so that the seawater can be used as a water source for the methanol reforming hydrogen production reaction. The operating temperature of each device in the external freshwater production system is kept at room temperature, and the pressure is kept at 1 atm.

[0057] The present invention is based on a compact marine carbon capture system or method based on the combination of methanol reforming and highly efficient membrane separation, and provides a safe hydrogen-based methanol reforming hydrogen production internal combustion engine powering method for marine vessels, including the following steps: Step 1: First, pre-charge the battery so that it can provide the required power throughout the entire process. Step 2: Control the battery pack to turn on the power, and supply power from the battery pack to the methanol reforming hydrogen production module to start the methanol reforming hydrogen production process; Step 3: After the methanol steam reforming hydrogen production module reaches the set temperature, hydrogen is quickly released and supplied to the hydrogen buffer tank, which is equipped with a pressure detection device, a temperature detection device, and a density detection device to ensure the safety and efficiency of operation. Then, the internal combustion engine is started to supply kinetic energy to the drive system. Step 4: After the methanol steam reforming hydrogen production module starts to output hydrogen normally, the residual heat of the exhaust gas from the internal combustion engine can be used to supply heat to the reforming reaction module, thereby cutting off the output of the battery module (during this process, the battery module is regarded as a backup power source and is on standby at any time); and Step 5: The central display console automatically adjusts the hydrogen filling and discharging mass of the hydrogen buffer tank and the output of the internal combustion engine according to the ship's real-time situation, and if there is spare capacity in the internal combustion engine's export power, the system will start charging the battery modules.

[0058] In the above process, an intelligent control method is used to perform multivariate control of a compact marine carbon capture system based on the combination of methanol reforming and highly efficient membrane separation. The construction steps of the intelligent control method are as follows: S1: Install online monitoring equipment for core equipment of the system, such as the hydrogen buffer tank, methanol reformer, membrane separator, and ship engine. Combine the design parameters of the core equipment of the system with navigation know-how to build a data middle office that includes important parameters of processes such as methanol reforming, highly efficient membrane separation of reformed products, and ship power generation, and realize data collection, governance, analysis and mining, etc., to give the system the power to control intelligently. S2: Study the coupling relationship between the compact reforming reactor, compact membrane separation device, ship power generation, high-efficiency and low-energy consumption carbon dioxide compression and storage device and hydrogen buffer tank, etc., identify the key factors that affect the low-energy consumption and stable operation of the above devices, and build a knowledge and data fusion-driven key parameter model for compact ship carbon capture control; The parameters of the key parameter model of the knowledge and data fusion driven compact marine carbon capture control include carbon capture efficiency η CO2 , the operating temperature of the superheater T s , methanol water vapor flow rate V m , the operating temperature of the reforming reaction T m , reforming reactor operating pressure P m , gas flow velocity inside the membrane V s、 Engine output W e、 Ship exhaust gas temperature T T , H2 recovery amount after membrane separation L n and the formula is expressed as follows:

[0059]

number

[0060] S3: Further study the key indicators of efficiency-energy consumption-material consumption under operating conditions, and establish an energy flow and material flow cost evaluation model for a compact marine carbon capture system based on the combination of methanol reforming and highly efficient membrane separation. The equations for the energy flow cost E and material flow cost C evaluation model are expressed as follows:

[0061] E=E f +E P +E h +E v +E h1 +E r +E s +E c +E h2 +E a

[0062] Energy consumption: Booster fan power consumption Ef , Power consumption of transfer pump E p , power consumption of the first preheater E h , evaporator power consumption E v、 Superheater power consumption E h1 , the power consumption of the reforming reactor E r , power consumption of membrane separator E s , power consumption of the first compressor E c , Heater power consumption E h2 , power consumption of air transport fan E a、

[0063] C=C m +C w +C c +C s +C s +C l

[0064] Material consumption: Methanol C m , water C w , catalyst C c , Membrane Assembly C s , refrigerant C l ,

[0065] S4: Using the established energy consumption-material consumption comprehensive cost evaluation model of methanol steam reforming combined with membrane separation, carry out efficiency-energy consumption-material consumption analysis under the fluctuation of load / operating conditions, and find the optimal parameter combination of cost, to build a global optimization parameter model of the system under the fluctuation of load / operating conditions for efficiency-energy consumption-material consumption analysis, and find the global optimization parameters of the system to accurately evaluate the dynamic operating costs of all flows of the compact reforming reactor, compact membrane separation device, and ship power generation under different operating conditions in real time, comprehensively considering the stability and economic constraints of each device, and solving them through intelligent optimization algorithms including particle swarm and ant colony to obtain the optimal parameter combination of the energy consumption-material consumption comprehensive cost;

[0066] The energy and material consumption of each device is quantified by cost, and the complex physical problem is transformed into an economic problem. In the specific operation, the energy consumption (such as the power consumption of the booster fan, the power consumption of the transfer pump, etc.) and material consumption (such as methanol, water, catalyst, etc.) of each device are taken as variables, and the overall cost is taken as the optimization target. An overall cost function based on energy and material consumption is constructed, and then the function is solved by intelligent optimization algorithms such as particle swarm and ant colony, and the combination of parameters that minimizes the overall cost is found, thereby constructing a global optimization parameter model of the system under the variation of load / operating conditions for efficiency-energy consumption-material consumption analysis;

[0067] Cost-performance optimization problem of a coupled system of methanol steam reforming and product membrane separation: minE=E f +E P +E h +E v +E h1 +E r +E s +E c +E h2 +E a minC=C m +C w +C c +C s +C s +C l

number

[0068] S5: After obtaining the optimal parameter combination of the total cost of energy consumption and material consumption, construct an optimization objective function and solve the optimization problem with a multi-objective optimization algorithm to further realize the strategy formulation. The strategy implements collaborative optimization among multiple devices such as reforming reactor, compact membrane separator and ship power generation under the multi-objective constraint of energy consumption-material consumption-carbon emission, and provides real-time guidance for flexible adjustment of key parameters of the core devices of the system under the fluctuation of load / operating conditions to further reduce material consumption and energy consumption. Based on the above optimization parameter model, a coordinated optimization strategy between multiple devices, namely, a reforming reactor, a compact membrane separation device and a ship power generation device, is established under the multi-objective goal of energy consumption-material consumption-carbon emission. In this strategy, a multi-objective optimization model is established with energy consumption, material consumption and carbon emission as optimization goals. This model requires finding a parameter combination that optimizes the overall performance of these three goals on the premise of satisfying the operation requirements and environmental constraints of the device. After finding the optimal parameter combination, it is solved by an intelligent optimization algorithm and combined with the actual operating conditions to provide real-time guidance for flexible adjustment of the key parameters of the core devices of the system under load fluctuations, and provides real-time guidance for flexible adjustment of the key parameters of the core devices of the system under load / operating condition fluctuations, thereby further reducing material consumption and energy consumption.

[0069] The present invention proposes a compact marine carbon capture system based on the combination of methanol reforming and highly efficient membrane separation, which is equipped with a reforming hydrogen production reactor that can produce hydrogen-rich reformed gas through methanol-water vapor reaction, and is provided with a heat supply gas passage that receives high-temperature exhaust gas from an internal combustion engine, and distributes the received high-temperature exhaust gas through an exhaust gas distributor to the reforming hydrogen production reactor and the methanol aqueous solution storage tank according to the needs of the chemical reaction environment.

[0070] The present invention provides an effective and innovative pre-combustion carbon capture process for ships, realizing the safe storage, transportation and pre-combustion carbon capture of ship fuel in the propulsion system. The present invention uses methanol water as raw material, and performs reforming reaction in a methanol reformer to generate hydrogen, and then converts the hydrogen into power in a hydrogen internal combustion engine, thereby realizing the direct utilization of hydrogen energy. This innovative methanol hydrogen production system enables ships to directly utilize hydrogen energy without filling hydrogen, effectively solving the hydrogen filling problem faced in the development of traditional hydrogen fuel cells. In addition, the present invention enables ships to be powered by hydrogen, effectively avoiding the situation where the carbon emissions of ships do not meet environmental protection standards. Through a series of optimization measures, the present invention shows remarkable benefits in many aspects, such as reducing greenhouse gas emissions, reducing dependence on fossil fuels, capturing carbon dioxide, and improving the energy utilization efficiency and cruising range of ships. This not only contributes to promoting the green, low-carbon and sustainable development of the shipping industry, but also provides practical technical means for the global response to climate change. EXAMPLES

[0071] Two major industrial fuels, heavy oil and methanol, were considered. The specific process parameters were as follows: In the methanol steam reforming reaction, a copper-zinc-aluminum catalyst doped with cerium and niobium was used, which can achieve excellent performance at temperatures of 180°C-280°C and pressures of 0.1MPa-3MPa. At the same time, in order to improve the separation efficiency of carbon dioxide, a MOF reformed gas separation membrane with high selectivity and high permeability was used for membrane separation. The optimal selection was obtained by comparing the effects of different fuels on carbon emission reduction and greenhouse gas emission rate after combustion and reforming.

[0072] Figure 5 shows the impact of different fuels and carbon capture technologies on carbon emission reduction effect and greenhouse gas emissions. The horizontal axis represents the carbon emission reduction method, and the vertical axis represents the proportion of greenhouse gas emissions. According to the calculation results, the greenhouse gas emissions of heavy oil fuel were set as 100% of the baseline. When methanol was used as fuel, greenhouse gas emissions could be reduced by up to 75%, that is, compared with heavy oil, greenhouse gas emissions could be effectively reduced by 25%. When carbon capture technology was adopted after heavy oil combustion, greenhouse gas emissions could be further reduced by up to 60%. Similarly, when post-combustion carbon capture technology based on methanol fuel was used, greenhouse gas emissions could be reduced by up to 50%. Finally, when methanol reforming was used in combination with pre-combustion carbon capture technology (the present invention), greenhouse gas emissions could be reduced by up to 2%, that is, the carbon emission reduction effect reached more than 98%. This shows that the combination of methanol reforming and pre-combustion carbon capture technology has significant advantages in reducing greenhouse gas emissions. Therefore, consideration of the use of the methanol reforming + pre-combustion carbon capture process in industrial applications could provide significant environmental, safety, and economic benefits.

[0073] The above-mentioned embodiments are merely for clarifying the technical means of the present application, and should not be interpreted narrowly as being limited to such specific examples. Although the present application has been described in detail with reference to the above-mentioned embodiments, it will be understood by those skilled in the art that the technical means described in the above-mentioned embodiments may be modified or equivalently replaced with part or all of the technical features, and such modifications or replacements do not cause the essence of the corresponding technical means to depart from the scope of the technical means of each embodiment of the present application.

Claims

1. A marine pre-combustion carbon capture system comprising a compact reforming reactor, a compact membrane separation device, a highly efficient and low energy consumption carbon dioxide compression and storage device, and a hydrogen buffer tank, The compact reforming reactor is used to produce hydrogen and carbon dioxide through a steam reforming reaction after mixing methanol and water. The compact membrane separation device is used to separate the produced hydrogen and carbon dioxide. The highly efficient, low energy consumption carbon dioxide compression and storage device compresses and stores the separated carbon dioxide. The hydrogen buffer tank is used to store and transport separated hydrogen to the ship engine system. The compact type reforming reactor includes a methanol aqueous solution storage tank, a first preheater, an evaporator, a superheater, a reforming reactor, and a first condenser, which are sequentially connected to each other, and the first condenser is also connected to the first preheater, the evaporator, and the superheater, respectively; The compact membrane separation apparatus includes a first mixing tank, a first gas-liquid separator, a membrane separator, a first compressor, a second condenser, a second gas-liquid separator, and a heater, which are sequentially connected to each other, the heater being connected to the first mixing tank, and the second gas-liquid separator being connected to a carbon dioxide compression and storage apparatus; The high-efficiency, low-energy-consumption carbon dioxide compression and storage device includes a second compressor, a first heat exchanger, a third gas-liquid separator, a third compressor, a second heat exchanger, a fourth gas-liquid separator, and a third condenser, which are sequentially connected to each other, and the third condenser is connected to a carbon dioxide storage tank; One end of the hydrogen buffer tank is connected to the membrane separator, and the other end is connected to a first flow divider, which is connected to a gas-fired boiler and an engine, respectively. High-temperature flue gas generated from the gas-fired boiler and the engine enters and is mixed in a second mixing tank, which is also connected to a first preheater, an evaporator, a superheater, and a reforming reactor, respectively. A compact marine carbon capture system based on the combination of methanol reforming and highly efficient membrane separation.

2. 2. The compact marine carbon recovery system based on the combination of methanol reforming and highly efficient membrane separation according to claim 1, wherein the reforming reactor has a membrane and a catalyst unit inside, the membrane is used to fix the catalyst and uniformly distribute the reactants, the catalyst unit includes a catalytic reforming region, and the outer periphery of the catalytic reforming region is a heating region, which receives high-temperature flue gas to supply required heat energy to the catalytic reforming region.

3. The high-efficiency, low-energy-consumption carbon dioxide compression and storage device further includes a first heat exchanger, a second heat exchanger, an absorber, a third heat exchanger, a solution pump, a reboiler, a generator, an absorbent recovery device, a fourth heat exchanger and a throttle valve, in which the first heat exchanger and the second heat exchanger are used for cooling by seawater spray, the absorber is used for absorbing refrigerant from the refrigeration cycle pipeline, the third heat exchanger is used for adjusting the temperature of the whole device, the solution pump is used for transporting liquid, the reboiler is used for heating the refrigerant, the generator is used for generating the required refrigerant, the absorbent recovery device is used for collecting and recovering the absorbent, the fourth heat exchanger is used for controlling the heat exchange of the device, and the throttle valve is used for adjusting and controlling the flowing refrigerant. The compact marine carbon capture system based on the combination of methanol reforming and highly efficient membrane separation as claimed in claim 1.

4. 2. The compact marine carbon recovery system based on the combination of methanol reforming and highly efficient membrane separation as claimed in claim 1, wherein the volume ratio of methanol to water in the methanol aqueous solution storage tank is 6:

4.

5. The method comprises the steps of: (1) Production of hydrogen and carbon dioxide using methanol steam reforming reaction: Methanol and water are mixed and subjected to a steam reforming reaction via a catalyst at a temperature of 180°C to 280°C and a pressure of 0.1 MPa to 3 MPa to produce hydrogen and carbon dioxide; (2) Separation of the produced hydrogen and carbon dioxide using membrane separation technology: Hydrogen and carbon dioxide are separated through a membrane material with selectivity and permeability; (3) Realization of carbon capture by compressing and storing the separated carbon dioxide: Compressing the carbon dioxide with a purity of 98% or more generated during the membrane separation process and converting it into liquid carbon dioxide, and then storing the compressed carbon dioxide in a storage tank for future carbon dioxide containment or other carbon dioxide uses; and (4) Transporting the separated hydrogen to the ship's fuel system and using it as fuel: The separated hydrogen will be transported through a pipeline to the ship's fuel system, and the hydrogen will be used as clean fuel in the ship's engine system, achieving low-carbon and zero-emission operation of the ship. A compact marine carbon capture method based on the combination of methanol reforming and highly efficient membrane separation, comprising:

6. The catalyst in the step (1) is a copper-zinc-aluminum catalyst doped with cerium and niobium, and the catalyst is composed of CuO having a mass fraction of 30% to 45%, ZnO having a mass fraction of 25% to 45%, Al having a mass fraction of 10% to 20%, and CuO having a mass fraction of 25% to 45%. ２ O ３ , 0.1% to 3.5% CeO ２ and 0.1% to 2.5% Nb ２ O ５ It is prepared by mixing, drying and roasting The membrane material in the step (2) is a MOF reformed gas separation membrane, and the MOF reformed gas separation membrane is prepared through the following steps: (a) adding the activated MOF powder to acetone and dispersing the MOF in acetone by water bath sonication to form a MOF ink, where the concentration of MOF in acetone is 5 g / L-30 g / L; (b) adding polyvinylidene fluoride to water and stirring to form a viscous membrane solution with a concentration of 6 wt % to 10 wt %; (c) adding the film liquid to the MOF ink, and continuing ultrasonic treatment to remove acetone in the mixed solution to obtain a viscous cast liquid; (d) Pour the casting liquid onto a glass plate to form a film of 200 μm to 300 μm, then place in an oven at 60° C. to 80° C. to preheat, and remove the film after the water has completely evaporated. (e) The membrane from step (d) is placed in a glass ring on a Teflon plate, and a previously prepared 3 wt% polyimide solution is added, and then the Teflon plate is placed in an oven at 60-90°C to remove the polyimide, thereby obtaining a MOF reformed gas separation membrane. The method for carbon recovery for compact ships based on the combination of methanol reforming and highly efficient membrane separation according to claim 5.

7. 6. The method for carbon recovery for a compact ship based on the combination of methanol reforming and highly efficient membrane separation according to claim 5, further comprising an external water production system for converting seawater into fresh water through reverse osmosis equipment so that the seawater can be used as a water source for the methanol steam reforming hydrogen production reaction, and the operating temperatures of each device in the external water production system are all kept at room temperature and the pressure is kept at 1 atm.

8. A method for applying a compact marine carbon capture system based on the combination of methanol reforming and highly efficient membrane separation as claimed in claim 1, comprising the following steps: (1) First, pre-charge the battery so that it can provide the required power throughout the entire process; (2) controlling the battery pack to turn on the power and supply power from the battery pack to the methanol reforming hydrogen production module to start the methanol reforming hydrogen production process; (3) After the methanol steam reforming hydrogen production module reaches a set temperature, hydrogen is quickly released and supplied to the hydrogen buffer tank, and then the internal combustion engine is started to supply kinetic energy to the drive system; (4) After the methanol steam reforming hydrogen production module starts to normally deliver hydrogen, the residual heat of the exhaust gas from the internal combustion engine can be used to supply heat to the reforming reaction module, thereby cutting off the output of the battery module (during this process, the battery module is regarded as a backup power source and is on standby at any time); (5) The central display console automatically adjusts the hydrogen filling and discharging mass of the hydrogen buffer tank and the output of the internal combustion engine according to the real-time situation of the ship. When there is a surplus in the export power of the internal combustion engine, the system starts charging the battery modules. Including, The whole process is multivariately controlled by an intelligent control method to realize a compact marine carbon capture system based on the combination of methanol reforming and highly efficient membrane separation. The present invention relates to an application method for a compact marine carbon capture system based on the combination of methanol reforming and highly efficient membrane separation.

9. The construction procedure of the intelligent control method is as follows: S1: Install online monitoring equipment for the core equipment of the system, including the hydrogen buffer tank, compact reforming reactor, membrane separation device, and ship engine, and further combine the design parameters of the core equipment of the system with navigation know-how to establish a data middle office containing important parameters of methanol reforming, highly efficient membrane separation of reformed products, and ship power generation process; S2: Study the coupling relationship between the compact reforming reactor, the compact membrane separation device, the ship power generation, the high-efficiency and low-energy consumption carbon dioxide compression and storage device and the hydrogen buffer tank, identify the key factors that affect the low-energy consumption and stable operation of the core devices of the above system, and build a knowledge and data fusion-driven key parameter model of compact ship carbon capture control; The key parameters of the knowledge and data fusion driven compact marine carbon capture control model include carbon capture efficiency η ＣＯ２ , the operating temperature of the superheater T ｓ , methanol water vapor flow rate V ｍ、 Reforming reaction operating temperature T ｍ、 Reforming reactor operating pressure P ｍ , gas flow velocity inside the membrane V ｓ , engine output W ｅ、 Ship exhaust gas temperature T Ｔ , H after membrane separation ２ Recovery amount L ｎ and the formula is expressed as follows: [0010] S3: Further study the key indicators of efficiency-energy consumption-material consumption under operating conditions, and establish an energy flow and material flow cost evaluation model for a compact marine carbon capture system based on the combination of methanol reforming and highly efficient membrane separation. The formulas for the energy flow cost E and material flow cost C evaluation model are expressed as follows: E=E ｆ +E Ｐ +E ｈ +E ｖ +E ｈ１ +E ｒ +E ｓ +E ｃ +E ｈ２ +E ａ Energy consumption: Power consumption of booster fan E ｆ , Power consumption of transfer pump E Ｐ、 Power consumption E of the first preheater ｈ , power consumption of the evaporator E ｖ , power consumption of the superheater E ｈ１ , the power consumption of the reforming reactor E ｒ , power consumption of membrane separator E ｓ , power consumption of the first compressor E ｃ , the power consumption of the heater E ｈ２、 Power consumption of air transport fan E ａ、 C=C ｍ +C ｗ +C ｃ +C ｓ +C ｓ +C ｌ Material consumption: Methanol C ｍ , water C ｗ , catalyst C ｃ , Membrane Assembly C ｓ , refrigerant C ｌ , S4: Using the established energy consumption-material consumption comprehensive cost evaluation model of methanol steam reforming combined with membrane separation, carry out efficiency-energy consumption-material consumption analysis under the fluctuation of load / operating conditions, and find the optimal parameter combination of cost, to build a global optimization parameter model of the system under the fluctuation of load / operating conditions for efficiency-energy consumption-material consumption analysis, and find the global optimization parameters of the system to accurately evaluate the dynamic operating costs of all flows of the compact reforming reactor, compact membrane separation device, and ship power generation under different operating conditions in real time, and comprehensively consider the stability and economic constraints of each device, and solve them through intelligent optimization algorithms including particle swarm and ant colony to obtain the optimal parameter combination of the energy consumption-material consumption comprehensive cost; Cost-performance optimization problem for a coupled system of methanol steam reforming and product membrane separation: minE=E ｆ +E Ｐ +E ｈ +E ｖ +E ｈ１ +E ｒ +E ｓ +E ｃ +E ｈ２ +E ａ minC=C ｍ +C ｗ +C ｃ +C ｓ +C ｓ +C ｌ [0025] Wherein, carbon recovery efficiency n ｃ ≧97%, reforming reaction conversion rate n ｍ ≧95%, membrane separation efficiency n Ｓ ≧90%, reforming reactor operating pressure P ｍ 0.1MPa to 3MPa, catalyst operating temperature T ｍ The constraint is 180°C to 280°C. S5: After obtaining the optimal parameter combination of the total cost of energy consumption-material consumption, construct an optimization objective function, and solve the optimization problem with a multi-objective optimization algorithm to further realize the strategy formulation, which implements collaborative optimization among multiple devices such as reforming reactor, compact membrane separator, and ship power generation under the multi-objective constraint of energy consumption-material consumption-carbon emission, and provides real-time guidance for flexible adjustment of key parameters of core devices of the system under changing load / operating conditions to further reduce material consumption and energy consumption. The application method of the compact marine carbon capture system based on the combination of methanol reforming and highly efficient membrane separation according to claim 8.

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