On-board exhaust gas carbon capture system and its applications

Abstract

The application provides a vehicle-mounted tail gas carbon capture system and application thereof, and relates to the technical field of carbon capture and resource utilization. The vehicle-mounted tail gas carbon capture system comprises, in sequence according to the order of tail gas passing, a temperature control module, a dehydration module, an adsorption / desorption double module and a carbon dioxide storage tank. The temperature control module is used for reducing the temperature of tail gas to below 40 DEG C. The dehydration module is used for reducing the humidity of tail gas to below 40%. The adsorption / desorption double module is used for adsorbing and capturing carbon dioxide in tail gas and / or desorbing and releasing carbon dioxide. The carbon dioxide storage tank is used for collecting the desorbed and released carbon dioxide. The vehicle-mounted tail gas carbon capture system faces the real driving scene of a vehicle, is modularly designed, is suitable for vehicle-mounted installation, can not only improve the carbon dioxide (CO2) capture efficiency, but also can realize continuous operation, regeneration without shutdown, and is controllable in material cost, adjustable in performance, and beneficial to the closed-loop recycling of carbon resources.

Description

Technical Field

[0001] This invention relates to the technical field of carbon capture and resource utilization, and in particular to a vehicle exhaust carbon capture system and its application. Background Technology

[0002] The automotive industry plays a crucial role in achieving carbon peaking and carbon neutrality. Currently, a two-pronged approach to emissions reduction is being adopted: first, promoting the replacement of traditional gasoline-powered vehicles globally through electrification to reduce carbon emissions from the energy consumption side; second, continuously developing low-carbon manufacturing technologies to optimize the carbon emission intensity of the production process.

[0003] The application of carbon capture, utilization, and storage (CCUS) technology to the automotive sector still faces significant techno-economic bottlenecks. Traditional exhaust carbon capture technologies have not yet achieved large-scale deployment due to high energy consumption and low cost-effectiveness. While existing mainstream technologies can convert CO2 into carbonates through catalytic reactions and further hydrogenate to produce methanol or alkanes for adsorbent regeneration, their adoption is constrained by two factors: first, the automotive industry has not yet established a mature hydrogen-powered braking system; second, the introduction of external hydrogen significantly increases technological complexity and safety risks, and drives up overall costs, making it difficult for the net benefits of the technology to reach the commercialization threshold.

[0004] Currently, common carbon dioxide capture devices, especially systems designed for mobile sources such as vehicle exhaust, generally face the following challenging problems in practical applications: (1) The temperature and humidity of automobile exhaust are very high; the adsorption material used, such as solid amine material, is based on the adsorption principle of a reversible chemical reaction between amine and CO2. This reaction can only proceed smoothly at low temperature. If the temperature is too high, the adsorption effect will be greatly reduced. At the same time, water vapor in the exhaust gas will compete with CO2 for the active sites on the amine, further reducing the capture efficiency. Most existing devices do not perform effective pretreatment for the high temperature and high humidity of automobile exhaust, but directly put the material in, resulting in the actual CO2 captured being far lower than the ideal value measured in the laboratory. (2) Existing technologies for exhaust gas cooling and dehumidification are not suitable for use in vehicles. For example, existing technologies use a separate cooler. After cooling, condensate may be released in the exhaust gas, which can easily enter the adsorption module and damage the solid amine material or the carrier structure. In addition, in existing technologies, the cooling, dehydration and adsorption steps are often separate, with complex pipelines in between. This not only takes up space but is also prone to leakage and pressure loss. This loose arrangement makes it difficult to achieve true integration. (3) When using solid amine adsorption, the principle is to switch between low-temperature adsorption and high-temperature regeneration. However, in actual devices, the airflow distribution and heat transfer structure in the adsorption bed are not well considered. For example, after the gas enters, it may take a short circuit, with some places being too cold and others being too hot, resulting in uneven material utilization. At the same time, the heating method during regeneration is relatively crude, and the energy consumption is not low. If the waste heat of automobile exhaust is used to drive regeneration, this crude heating method will make it difficult to efficiently utilize the limited heat. In addition, the operating conditions of automobiles vary greatly, such as idling, acceleration, and constant speed. Existing devices lack the ability to dynamically control the adsorption and desorption processes. When the operating conditions change, the performance fluctuates, and the stability is poor. (4) From the perspective of the whole device, the existing technology has not truly integrated the functions of cooling, dehumidification, adsorption and regeneration into a compact module. Most of them still disperse the functional units, which not only leads to large size and difficult assembly, but also causes maintenance trouble. At the same time, the risk of pressure drop and leakage also increases, and true vehicle application cannot be realized.

[0005] In view of this, the present invention is hereby proposed. Summary of the Invention

[0006] One of the objectives of this invention is to provide an on-board carbon capture system for vehicle exhaust, designed for real-world driving scenarios, with a modular design suitable for on-board installation. It can improve carbon dioxide (CO2) capture efficiency, enable continuous operation without shutdown for regeneration, and facilitate the closed-loop recycling of carbon resources.

[0007] The second objective of this invention is to provide an application of an on-board exhaust carbon capture system, which has the same advantages as the aforementioned system, and will not be elaborated further here.

[0008] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted: In the first aspect, an on-board exhaust carbon capture system includes, in the order of exhaust gas passage, a temperature control module, a dehydration module, an adsorption / desorption dual module, and a carbon dioxide storage tank. The temperature control module is used to reduce the exhaust gas temperature to below 40°C; The dehydration module is used to reduce the humidity of the exhaust gas to below 40%; The adsorption / desorption dual module is used to adsorb and capture carbon dioxide in the exhaust gas and / or desorb and release carbon dioxide. The carbon dioxide storage tank is used to collect the carbon dioxide released during desorption.

[0009] Furthermore, the temperature control module and the dehydration module are composed of an integrated structure.

[0010] Furthermore, the desiccant in the dehydration module includes at least one of silica gel and molecular sieve.

[0011] Furthermore, the adsorption / desorption dual module adopts a fixed bed structure; Preferably, the thickness of the bed layer in the fixed bed structure is 10cm-15cm, and the porosity is 0.3-0.4.

[0012] Furthermore, the adsorption / desorption dual module contains at least one of the following adsorption and trapping materials: solid amine, mesoporous carbon, modified activated carbon, zeolite, modified zeolite, modified calcium-based material, and alkali metal carbonate.

[0013] Furthermore, the air inlet of the adsorption / desorption dual module is equipped with a three-way valve, which allows the exhaust gas to freely switch its flow to either of the dual modules.

[0014] Furthermore, the outlet of the adsorption / desorption dual module is equipped with a three-way valve, which allows carbon dioxide to freely switch its flow direction to the carbon dioxide storage tank and / or be directly discharged.

[0015] Furthermore, the carbon dioxide storage tank is filled with an ionic liquid, thereby enabling the carbon dioxide to be chemically absorbed.

[0016] Furthermore, the carbon dioxide storage tank is equipped with an electrochemical module, thereby enabling the electrocatalytic production of gasoline from carbon dioxide.

[0017] Secondly, the application of any of the above-mentioned vehicle exhaust carbon capture systems in automobile exhaust treatment.

[0018] Compared with the prior art, the present invention has at least the following beneficial effects: The vehicle-mounted exhaust carbon capture system provided by this invention is designed for real-world automotive driving scenarios. Its modular design makes it suitable for vehicle installation. It not only addresses the high temperature and humidity issues of automotive exhaust—with a temperature control module reducing exhaust temperature to below 40°C and a dehydration module reducing humidity to below 40%—effectively improving carbon dioxide (CO2) capture efficiency under low temperature and low humidity conditions. Furthermore, the system allows for continuous operation without downtime for regeneration through the free switching between adsorption and desorption modules. It also utilizes modular, replaceable capture materials, achieving efficient CO2 capture through a combination of physical and chemical methods. This provides a general technical platform for verifying the performance of capture materials, and ensures a clear destination for the recovered CO2. In summary, this vehicle-mounted exhaust carbon capture system, designed for real-world automotive driving scenarios, not only improves CO2 capture efficiency but also enables continuous operation without downtime for regeneration. Moreover, it offers controllable material costs, adjustable performance, and facilitates the closed-loop recycling of carbon resources.

[0019] The application of the vehicle exhaust carbon capture system provided by this invention has the same advantages as the above-mentioned systems, which will not be repeated here. Attached Figure Description

[0020] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific 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 from these drawings without creative effort.

[0021] Figure 1 An external shape diagram of a vehicle exhaust carbon capture system provided in one embodiment of the present invention; Figure 2 An external shape diagram of a vehicle exhaust carbon capture system provided in one embodiment of the present invention; Figure 3 An external shape diagram of a vehicle exhaust carbon capture system provided in one embodiment of the present invention; Figure 4 An external shape diagram of a vehicle exhaust carbon capture system provided in one embodiment of the present invention; Figure 5 An external shape diagram of a vehicle exhaust carbon capture system provided in one embodiment of the present invention; Figure 6 An external shape diagram of a vehicle exhaust carbon capture system provided in one embodiment of the present invention; Figure 7 An external shape diagram of a vehicle exhaust carbon capture system provided in one embodiment of the present invention; Figure 8 A schematic diagram illustrating the working principle of a vehicle exhaust carbon capture system according to one embodiment of the present invention. Detailed Implementation

[0022] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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.

[0023] According to a first aspect of the present invention, an on-board exhaust carbon capture system is provided, which, in the order of exhaust gas passage, includes a temperature control module, a dehydration module, an adsorption / desorption dual module, and a carbon dioxide storage tank. The temperature control module is used to reduce the exhaust gas temperature to below 40°C; The dehydration module is used to reduce the humidity of exhaust gas to below 40%; The adsorption / desorption dual module is used to adsorb and capture carbon dioxide in the exhaust gas and / or desorb and release carbon dioxide. Carbon dioxide storage tanks are used to collect carbon dioxide released during desorption.

[0024] The functional units of temperature control, dehydration, adsorption, desorption (regeneration) and storage tank are built into independently detachable modules, and the connections between modules can be made compact, making them suitable for vehicle installation.

[0025] The vehicle exhaust carbon capture system provided by this invention is designed for real-world automotive driving scenarios. Its modular design makes it suitable for vehicle installation. It can not only address the high temperature and high humidity issues of automotive exhaust, with a temperature control module reducing exhaust temperature to below 40°C and a dehydration module reducing exhaust humidity to below 40%, but also effectively improve carbon dioxide (CO2) capture efficiency under low temperature and low humidity conditions. Furthermore, it can achieve continuous operation without downtime for regeneration through the free switching between adsorption / desorption modules. It can also use modular and replaceable capture materials, achieving efficient CO2 capture from exhaust through a combination of physical and chemical methods. It also provides a general technical platform for verifying the performance of capture materials, and the recovered CO2 has a clear destination.

[0026] In summary, the vehicle exhaust carbon capture system of this invention is designed for real-world driving scenarios. It not only improves carbon dioxide capture efficiency but also enables continuous operation without the need for downtime regeneration. Furthermore, it offers controllable material costs, adjustable performance, and facilitates the closed-loop recycling of carbon resources.

[0027] In this invention, the automobile exhaust gas (around 100°C) is first cooled to below 40°C by a temperature control module. After the temperature is lowered, condensate is released and then removed by a dehydration module, reducing the humidity to below 40%. This is more conducive to improving the carbon dioxide capture efficiency of the subsequent adsorption / desorption dual modules, ensuring that the capture efficiency reaches more than 90%. For example, solid amine materials can be used to capture carbon dioxide. Solid amine materials can perform stably within a low temperature window of 40°C-60°C, which is more conducive to ensuring that the capture efficiency reaches more than 90%.

[0028] In a preferred embodiment, the temperature control module and the dehydration module can be made into an integrated structure, with no excessively long pipes left between them, thereby avoiding secondary condensation.

[0029] The temperature control module and the dehydration module are integrated into one structure, with the two modules side by side and closely attached. Valves and pipelines are centrally arranged, resulting in a smaller overall volume.

[0030] The modular design facilitates disassembly and maintenance, and the compact structure makes it suitable for vehicle installation.

[0031] The desiccant in the dehydration module includes, but is not limited to, at least one of silica gel and molecular sieve.

[0032] In a preferred embodiment, the adsorption / desorption dual module can be a fixed bed structure.

[0033] The adsorption / desorption dual module includes a left module and a right module, which can be arranged side by side. The module adopts a fixed bed structure with a bed thickness of 10cm-15cm and a porosity of 0.3-0.4, which is more conducive to improving the uniformity of airflow distribution and avoiding channeling or local overheating.

[0034] In a preferred embodiment, the adsorption and trapping materials in the adsorption / desorption dual module include, but are not limited to, at least one of solid amines, mesoporous carbon, modified activated carbon, zeolite, modified zeolite, modified calcium-based materials, and alkali metal carbonates.

[0035] Solid amines are composite structures consisting of a support and an amine source. The support provides the specific surface area and pores, while the amine source provides the active sites. Common support materials include Al2O3, SiO2, and activated carbon. Amine sources can be PEI (polyethyleneimine), TEPA (tetraethylenepentamine), TETA (triethylenetetramine), or mixtures thereof. Solid amines can be prepared by impregnation or in-situ polymerization, which is a simple and low-cost process. Furthermore, they can be adapted to different vehicle models and exhaust gas conditions by adjusting the amine source loading and support type, offering good flexibility. In conclusion, using solid amines as adsorbents, with their support-amine source composite structure, not only offers controllable costs but also adjustable performance.

[0036] In this invention, based on actual operating conditions (large fluctuations in exhaust gas temperature, high oxygen content, dust and water content, and limited space), the solid amine carrier can preferably be Al2O3 or Mg-Al mixed metal oxide, which is more conducive to balancing specific surface area, thermal stability and low cost; at the same time, the amine source can preferably be TEPA loaded on mesoporous SiO2, and the adsorption capacity can reach more than 3 mmol / g.

[0037] The solid amine support can be mesoporous SiO2 (specific surface area 300 m²). 2 / g-500m 2 / g, pore size 5nm-10nm), the amine source can be TEPA (tetraethylenepentamine); the mass ratio of TEPA to mesoporous SiO2 can be controlled between 40:60 and 60:40, which can ensure sufficient active sites without causing pore blockage due to excessive amine groups.

[0038] Solid amine adsorbent materials can be prepared through the following steps: First, add TEPA to anhydrous ethanol and stir until completely dissolved. Then, add mesoporous SiO2 to the solution and stir to allow the carrier to fully absorb the amine source. After that, the mixture is rotary evaporated in a water bath to remove most of the ethanol. Then, it is transferred to a vacuum drying oven for vacuum drying to completely remove the residual solvent. After natural cooling, it is sieved to remove large particles and powder, thus obtaining a solid amine adsorbent material.

[0039] In a preferred embodiment, the air inlet of the adsorption / desorption dual module can be equipped with a three-way valve, such as a three-way solenoid valve or a three-way pneumatic valve, so that the exhaust gas can be freely switched to either of the dual modules (left module and right module); the three-way valve can be automatically switched by the controller according to the adsorption time, bed temperature or carbon dioxide concentration. The controller's control logic is simple and reliable, does not rely on complex models, and judges the valve action by threshold, which is more reliable.

[0040] Due to the high vibration, drastic temperature changes, and severe electromagnetic interference in the vehicle environment, the controller can be treated with three-proof measures: moisture-proof, salt spray-proof, and mildew-proof. All wiring of the controller can use automotive-grade waterproof connectors. The controller's control logic can also be degraded, for example, using only a timer mode without relying on temperature or concentration signals.

[0041] In this invention, the adsorption / desorption dual module is switched via a three-way valve, enabling continuous operation without the need for shutdown regeneration. The left and right modules of the adsorption / desorption dual module are arranged side by side and can be quickly switched via the three-way valve. When one module is adsorbing and capturing carbon dioxide, the other module regenerates (desorbs and releases) carbon dioxide or stands by. When one module is saturated with carbon dioxide and enters the regeneration process, it switches to the other module to adsorb and capture carbon dioxide. This enables a cyclic process of "adsorption-switching-desorption-cooling-re-adsorption", allowing the system to operate continuously without interruption, which is very practical for scenarios with continuous exhaust from automobiles.

[0042] The temperature for regenerating (desorbing and releasing) carbon dioxide can be controlled between 120℃ and 150℃, which can not only desorb and release CO2 cleanly, but also prevent the amine groups from being overheated and degraded. Both the adsorption material and the system can operate stably for a long time.

[0043] This invention's system does not rely solely on electric heating; instead, it prioritizes utilizing the waste heat from automobile exhaust. Specifically, a high-temperature exhaust gas stream (150℃-250℃) is bypassed before the temperature control module, and its flow rate is controlled by a regulating valve. This gas is directed to the internal heat exchange pipes that require desorption, where it heats the saturated adsorption modules (120℃-150℃) through the heat exchange sleeve, thereby regenerating carbon dioxide. When the exhaust heat is insufficient, electric auxiliary heating can be used, employing a dual-source heating control strategy with exhaust heat as the primary source and electric auxiliary heating as a supplement. Simultaneously, the controller in this system automatically adjusts the heat source ratio based on real-time temperature. This significantly reduces the overall energy consumption of the system.

[0044] In a preferred embodiment, the outlet of the adsorption / desorption dual module can be equipped with a three-way valve, such as a three-way solenoid valve or a three-way pneumatic valve, so that carbon dioxide can freely switch its flow direction to the carbon dioxide storage tank and / or be directly vented.

[0045] In a preferred embodiment, the carbon dioxide storage tank may be filled with an ionic liquid, thereby enabling the carbon dioxide to be chemically absorbed.

[0046] The carbon dioxide storage tank is filled with chemical solvents. A one-way valve can be added to the tank inlet to prevent backflow of exhaust gas or solution. After carbon dioxide enters the storage tank, it will undergo a chemical absorption reaction with the chemical solvent, and thus be stored in the storage tank.

[0047] In this invention, the carbon dioxide storage tank can collect and hold 20%-40% of the carbon dioxide emitted by a car during its 100-200 km journey. The collected carbon dioxide can be further converted into fuels such as methane, methanol, and / or electrically generated gasoline using existing equipment.

[0048] In a preferred embodiment, an electrochemical module may be provided inside the carbon dioxide storage tank, thereby enabling the electrocatalytic production of gasoline from carbon dioxide.

[0049] The collected carbon dioxide will be further converted into electronic fuel (E-Fuel) through thermochemical / electrochemical conversion processes, thereby achieving closed-loop recycling of carbon resources.

[0050] In summary, the vehicle exhaust carbon capture system of this invention not only has the advantages of modularity and replaceable capture media, but also realizes carbon capture and storage in real driving scenarios, and provides a technical platform for the performance verification of capture materials. At the same time, it makes a substantial contribution to environmental protection and can further promote the transformation of the transportation sector from a "carbon emission source" to a "carbon cycle participant".

[0051] According to a second aspect of the present invention, an application of the vehicle exhaust carbon capture system described in any of the preceding claims in automobile exhaust treatment is provided.

[0052] The application of the vehicle exhaust carbon capture system of the present invention has the same advantages as the above-mentioned systems, which will not be repeated here.

[0053] The present invention will be further illustrated by the following examples. Unless otherwise specified, the materials in the examples are prepared according to existing methods or purchased directly from the market.

[0054] Example 1 A vehicle-mounted exhaust carbon capture system, the appearance of which is shown in the figure. Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 as well as Figure 7 According to the order of the exhaust gas passage, it includes a temperature control module, a dehydration module, an adsorption / desorption dual module, and a carbon dioxide storage tank. The temperature control module is used to reduce the exhaust gas temperature to below 40°C; The temperature control module is installed in the middle section of the exhaust pipe. The temperature of the exhaust gas coming out of the exhaust pipe is 120℃-200℃. After passing through the temperature control module, the temperature is reduced to below 40℃. The dehydration module is used to reduce the humidity of exhaust gas to below 40%; The dehydration module is immediately followed by the temperature control module. The temperature control module and the dehydration module are integrated into one structure and connected by a short pipe of no more than 20cm to avoid secondary heat absorption or condensation in the long pipeline after the exhaust gas is cooled. The dehydration module is filled with type A molecular sieve as a desiccant, with a thickness of 5cm-8cm. The exhaust gas (relative humidity 80%-90%) passes through it from bottom to top and the humidity is reduced to below 40% after passing through the dehydration module. The adsorption / desorption dual module is used to adsorb and capture carbon dioxide in the exhaust gas and / or desorb and release carbon dioxide. In the adsorption / desorption dual-module design, the left and right modules are arranged side-by-side. Each module is a fixed-bed reactor, and the interior is filled with solid amine as the adsorbent material. The solid amine is supported by mesoporous SiO2 (specific surface area 300 m² / g). 2 / g-500m 2 / g, pore size 5nm-10nm), the amine source is TEPA (tetraethylenepentamine), the mass ratio of TEPA to mesoporous SiO2 is 50:50; the bed thickness of the fixed bed reactor is 10cm-15cm, and the porosity is 0.3-0.4; at the same time, each module's air inlet and outlet are equipped with filters to prevent material particles from being carried out by the airflow; each module is equipped with an outer jacket, which can be used to pass high-temperature exhaust gas for heating and regeneration, and the jacket is covered with insulation cotton to reduce heat loss; The air inlet of the adsorption / desorption dual module is equipped with a three-way solenoid valve, which allows the exhaust gas to freely switch to either the left or right module. The three-way valve is automatically switched by the controller according to the adsorption time, bed temperature or carbon dioxide concentration, thus enabling continuous operation without stopping the machine for regeneration. Carbon dioxide storage tanks are used to collect carbon dioxide released (regenerated) during desorption; The carbon dioxide storage tank is filled with a chemical solvent—ionic liquid—and the tank opening is equipped with a one-way valve to prevent backflow of exhaust gas or solution; carbon dioxide enters the storage tank and undergoes a chemical absorption reaction with the chemical solvent, thereby being stored inside the tank.

[0055] Example 2 The difference between this embodiment and Embodiment 1 is that in this embodiment, the system fills the adsorption / desorption dual module with mesoporous carbon as the adsorption material. Everything else is the same as in Example 1.

[0056] Compared with the use of solid amine as adsorbent in Example 1, this example uses mesoporous carbon as adsorbent. Mesoporous carbon mainly relies on physical adsorption. In an environment with extremely low CO2 concentration (such as 400 ppm), its physical adsorption effect is very weak and its selectivity for CO2 is not high.

[0057] Example 3 The difference between this embodiment and Embodiment 1 is that in this embodiment, zeolite is filled inside the adsorption / desorption dual module as the adsorption material. Everything else is the same as in Example 1.

[0058] Compared with the use of solid amine as adsorbent in Example 1, this example uses zeolite as adsorbent. Zeolite has a much stronger affinity for water than for CO2. Water molecules will preferentially occupy the adsorption sites of zeolite, resulting in a sharp decrease in CO2 adsorption and seriously affecting its capture effect.

[0059] Example 4 The difference between this embodiment and Embodiment 1 is that the system in this embodiment is equipped with a three-way solenoid valve at the outlet of the adsorption / desorption dual module, so that carbon dioxide can freely switch its flow direction to the carbon dioxide storage tank and / or be directly discharged. Everything else is the same as in Example 1.

[0060] Example 5 The difference between this embodiment and Embodiment 1 is that the system in this embodiment has an electrochemical module in the carbon dioxide storage tank, thereby enabling the electrocatalytic production of gasoline from carbon dioxide. Everything else is the same as in Example 1.

[0061] In this embodiment, an electrochemical module is installed inside the carbon dioxide storage tank, which can directly convert the captured CO2 into E-fuel (electro-generated gasoline), and then directly return it to the engine as an energy source.

[0062] Comparative Example 1 The difference between this comparative example and Example 1 is that a temperature control module is not included in the system of this comparative example. Everything else is the same as in Example 1.

[0063] Compared with Example 1, the drawback of this comparative example is that it cannot effectively control the exhaust gas temperature. If the exhaust gas temperature is too high, the adsorption material will fail, and if the exhaust gas temperature is too low, the collection efficiency will be greatly reduced.

[0064] Comparative Example 2 The difference between this comparative example and Example 1 is that a dehydration module is not provided in the system of this comparative example. Everything else is the same as in Example 1.

[0065] Compared with Example 1, the drawback of this comparative example is that it cannot effectively control moisture. Water vapor can easily poison and deactivate the adsorbent material, resulting in the inability to effectively capture carbon dioxide.

[0066] Comparative Example 3 The difference between this comparative example and Example 1 is that the system in this comparative example does not have a dual adsorption / desorption module, but only a left or right module. Everything else is the same as in Example 1.

[0067] Compared with Example 1, the drawback of this comparative example is that it cannot achieve continuous operation and cannot capture carbon dioxide in the exhaust gas during desorption (regeneration), resulting in a significant reduction in the amount of carbon dioxide captured.

[0068] Test case The workflow of the vehicle exhaust carbon capture system in Example 1 is as follows: Figure 8 The control logic is as follows: 1. Initial State After the vehicle starts, the device automatically powers on. The initial settings are: the inlet three-way valve switches to the left adsorption module, and the right module is in standby mode. The temperature control module and dehydration module start working, and exhaust gas begins to enter the left module for adsorption.

[0069] 2. Adsorption stage The temperature inside the left module is maintained between 40℃ and 60℃ (the temperature control module keeps the inlet air temperature within this range). CO2 in the exhaust gas reacts with the amino groups on the solid amine material and is fixed. The controller monitors the bed temperature of the left module in real time; because the adsorption reaction is exothermic, the bed temperature rises slowly with increasing adsorption. The outlet CO2 concentration is also monitored simultaneously.

[0070] 3. Switch judgment The controller determines whether a switch is needed using any of the following methods: Method 1 (Time Control): Based on the preliminary calibration results, the left module will reach saturation in approximately 15-20 minutes under rated operating conditions. A timer is set on the controller to switch at the designated time. This method is the simplest and suitable for scenarios with relatively stable operating conditions.

[0071] Method 2 (Temperature Control): When the bed temperature is more than 8-10°C higher than the inlet air temperature and continues to rise, it indicates that the adsorption reaction is close to saturation and the exothermic reaction is weakening (in reality, the temperature rise rate slows down, which needs to be calibrated). The controller will switch when it detects this characteristic.

[0072] Method 3 (Concentration Control): When the outlet CO2 concentration exceeds 10% of the inlet concentration, it indicates penetration, and the system should be switched immediately. This method is the most accurate, but it requires an additional sensor.

[0073] 4. Switching Actions After the controller issues the switching command, the inlet three-way valve switches to the right module within 0.5 seconds, and the exhaust gas begins to enter the right module for adsorption. At the same time, the inlet valve of the left module closes, preparing to enter the desorption stage. There will be a brief overlap (about 1 second) during the switching process, and the inlet valves of both modules will open at a small angle to avoid sudden changes in pipeline pressure during the switching.

[0074] 5. Desorption stage After the left module is switched out, the controller opens the regulating valve on the high-temperature exhaust gas bypass pipeline. The bypassed high-temperature exhaust gas (temperature approximately 150℃-250℃, depending on engine operating conditions) is introduced into the jacket of the left module to heat the bed.

[0075] The controller adjusts the flow rate of the high-temperature exhaust gas based on real-time temperature feedback from the left-side module, aiming to stabilize the bed temperature between 120℃ and 150℃. The specific control logic is as follows: when the bed temperature is below 120℃, increase the flow rate of the high-temperature exhaust gas; when it is above 150℃, decrease the flow rate; if the high-temperature exhaust gas flow rate is already at its maximum but the temperature still doesn't rise (common in idling conditions), then activate the auxiliary electric heater.

[0076] At a temperature of 120℃-150℃, CO2 dissociates from the amino group. The dissociated CO2, along with a small amount of purge gas (which can be a small amount of fresh air or bypass tail gas that does not enter the adsorption module), is discharged from the outlet of the left module and enters the carbon dioxide storage tank through the outlet three-way valve.

[0077] During desorption, desorption is considered complete when the outlet CO2 concentration drops below 10% of the initial value. This can be determined by timing or by changes in bed temperature; when the temperature stops rising and begins to slowly decrease, the desorption reaction is essentially over.

[0078] 6. Cooling Phase After desorption is complete, the controller closes the high-temperature exhaust gas bypass valve, allowing the module to cool naturally. Once cooled to below 50°C, the left-side module enters standby mode, awaiting the next switchover.

[0079] 7. Circular operation Once the right module is saturated, the controller switches the exhaust gas back to the already cooled left module.

[0080] 8. Storage tanks Carbon dioxide storage tanks can collect and hold 20%-40% of the carbon dioxide emitted by a car during its 100-200 km journey. The collected carbon dioxide can be further converted into fuels such as methane, methanol, and / or electrically produced gasoline using existing equipment.

[0081] The operating parameters of the vehicle exhaust carbon capture system in Example 1 under typical operating conditions are as follows: Idle condition: Exhaust gas temperature: 100℃-120℃; Inlet air temperature (after temperature control): 40℃-45℃; Inlet relative humidity (after dehydration): 35%-40%; Desorption temperature: Mainly heated by residual heat, with electric assistance, and stabilized at around 120℃; Medium and high speed cruising conditions: Exhaust gas temperature: 150℃-200℃; Inlet air temperature (after temperature control): 40℃-45℃; Inlet relative humidity (after dehydration): 30%-35%; Desorption temperature: mainly based on exhaust gas waste heat, stable at around 115℃, electric heating basically not activated; Acceleration mode: The exhaust gas temperature instantly rises to over 200°C, and the temperature control module keeps the intake air temperature stable below 45°C. The adsorption time will be shortened and the switching frequency will be increased; The desorption and regeneration stage can be completed quickly using the high-temperature exhaust gas during acceleration.

[0082] The carbon dioxide capture efficiency of the systems in Example 1 and Comparative Examples 1-3 is shown in the table below.

[0083]

[0084] As can be seen from the data in the table, the carbon dioxide capture efficiency of the system in Example 1 is 90% or higher. Compared with the system in Example 1, if the system lacks a temperature control module, the adsorption material will completely fail, and the carbon dioxide capture efficiency will be 0. If the system lacks a dehydration module, although it will not significantly affect the capture efficiency of the adsorption material (solid amine), it will reduce the lifespan of the adsorption material. If the system lacks an adsorption / desorption dual module, the capture efficiency will be halved, and the carbon dioxide capture efficiency will be about 45%.

[0085] 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 vehicle-mounted exhaust carbon capture system, characterized in that, According to the order in which the exhaust gas passes, it includes a temperature control module, a dehydration module, an adsorption / desorption dual module, and a carbon dioxide storage tank. The temperature control module is used to reduce the exhaust gas temperature to below 40°C; The dehydration module is used to reduce the humidity of the exhaust gas to below 40%; The adsorption / desorption dual module is used to adsorb and capture carbon dioxide in the exhaust gas and / or desorb and release carbon dioxide. The carbon dioxide storage tank is used to collect the carbon dioxide released during desorption.

2. The vehicle exhaust carbon capture system according to claim 1, characterized in that, The temperature control module and the dehydration module are composed of an integrated structure.

3. The vehicle exhaust carbon capture system according to claim 2, characterized in that, The desiccant in the dehydration module includes at least one of silica gel and molecular sieve.

4. The vehicle exhaust carbon capture system according to any one of claims 1-3, characterized in that, The adsorption / desorption dual module adopts a fixed bed structure; Preferably, the thickness of the bed layer in the fixed bed structure is 10cm-15cm, and the porosity is 0.3-0.

4.

5. The vehicle exhaust carbon capture system according to claim 4, characterized in that, The adsorption / desorption dual module contains at least one of the following adsorption and trapping materials: solid amine, mesoporous carbon, modified activated carbon, zeolite, modified zeolite, modified calcium-based material, and alkali metal carbonate.

6. The vehicle exhaust carbon capture system according to claim 4, characterized in that, The air inlet of the adsorption / desorption dual module is equipped with a three-way valve, which allows the exhaust gas to freely switch to either of the two modules.

7. The vehicle exhaust carbon capture system according to claim 4, characterized in that, The outlet of the adsorption / desorption dual module is equipped with a three-way valve, which allows carbon dioxide to freely switch its flow direction to the carbon dioxide storage tank and / or be directly discharged.

8. The vehicle exhaust carbon capture system according to claim 1, characterized in that, The carbon dioxide storage tank is filled with an ionic liquid, which allows carbon dioxide to be chemically absorbed.

9. The vehicle exhaust carbon capture system according to claim 8, characterized in that, The carbon dioxide storage tank is equipped with an electrochemical module, which enables the electrocatalytic production of gasoline from carbon dioxide.

10. The application of the vehicle exhaust carbon capture system according to any one of claims 1-9 in automobile exhaust treatment.

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