Integrated system for DAC and building fresh air systems, and application

Abstract

Disclosed in the present invention are an integrated system for DAC and building fresh air systems, and an application. The integrated system comprises a fresh air system unit, wherein the fresh air system unit comprises an air supply system and an exhaust system. The integrated system further comprises: DAC capture and desorption devices which are arranged between the air supply system and an air inlet and at an outlet of the exhaust system, wherein each DAC capture and desorption device comprises an adsorption generator and a desorber which are connected in sequence, the adsorption generator being used for capturing carbon dioxide, and the desorber being used for desorbing and generating high-concentration carbon dioxide; and a compression and liquefaction subsystem, which is connected to a gas outlet of a carbon dioxide transport pipeline of each of the two DAC capture and desorption devices, and used for compressing and liquefying the desorbed carbon dioxide for storage and utilization. Relying on the fresh air system for air introduction, the present invention solves the key problem in DAC systems in respect of the energy consumption of air introduction, thereby lowering the carbon dioxide concentration in air introduced by the fresh air system while reducing the cost of DAC, improving the operational efficiency of the fresh air system, and enabling the capture of carbon dioxide from the air to achieve the goal of negative carbon emissions.

Description

DAC and building fresh air system integrated system and application TECHNICAL FIELD

[0001] The application relates to the fields of CO2 capture technology and building air conditioning technology, and particularly relates to a DAC and building fresh air system integrated system and application. BACKGROUND

[0002] Climate change is a severe challenge faced by mankind in the 21st century, and is a major global problem that deeply affects the ecological environment and economic and social development of countries. A large amount of greenhouse gases emitted by human activities is the main cause of global warming and climate change. Among them, the total CO2 emission is the largest, and the annual emission amount reaches more than 40 billion tons, which becomes the most important greenhouse gas leading to global warming. In 2023, the CO2 concentration in the global atmosphere has reached 420 ppm, which is the highest in the past 3 million years. The excessively high CO2 concentration will cause the temperature of the earth's surface to rise, further causing a series of serious problems such as glacier melting, land salinization, land drought, crop productivity decline and species extinction, and reducing the CO2 concentration in the atmosphere is imminent, which is a big problem faced by mankind.

[0003] Carbon capture, utilization and storage technology refers to the process of capturing CO2 emitted in the fields of energy, steel, cement, chemical industry, transportation and the like, then converting, utilizing or storing the captured CO2 in land and sea, so as to realize carbon emission reduction. According to the technical process, it can be divided into four important links of carbon capture, carbon transportation, carbon utilization and carbon storage. Carbon capture is the most basic link of the technology, which is the process of capturing CO2 from tail gas emitted in the processes of energy, steel, cement, chemical industry, transportation and the like, and separating and purifying.

[0004] Direct Air Capture (DAC) is a new technology of carbon capture technology. It transports air into the capture device through a huge fan array and captures CO2 using adsorbents (such as lye, organic amines, etc.), and the adsorbents that have adsorbed CO2 can be regenerated and reused by discharging CO2 through heating. DAC can effectively solve CO2 emissions from any source. As the world seeks to reduce carbon, even negative carbon, carbon emissions from some activities (such as long-distance air travel) are difficult to eliminate. This is where DAC can be used. In addition, DAC technology captures CO2 from air in a closed "chemical cycle" that can reuse adsorbents, minimizing waste. However, DAC technology also has a huge disadvantage: because the partial pressure of CO2 in the air is much smaller than that of flue gas from high-polluting sites such as coal-fired power plants, the concentration of CO2 is only 0.042% (420ppm), and about 1.3 million Nm3 of air needs to be transported to capture 1 ton of CO2, while the flue gas from coal-fired power plants (about 12% concentration), only 4550 Nm3 of flue gas is needed. Therefore, the cost of using fans to transport air and capture CO2 is very high. The current cost of DAC to capture one ton of CO2 from air is about $200-600, which is much higher than that of capturing CO2 from flue gas. The part of the cost that is higher is mainly concentrated in the power consumption of the fan. A simple calculation shows that the power consumption of the fan is more than 450 KWh / ton of CO2.

[0005] On the other hand, as living standards improve, people's demand for air quality in indoor places such as office buildings, shopping malls, hotels, airports, subway stations, and high-speed rail stations is also increasing, and the pollutants in the air in indoor places will accumulate and exceed the standard due to lack of air circulation. The fresh air system is a set of independent air handling system composed of a supply air system and an exhaust air system. It forms a "fresh air flow field" in the room by using special equipment to supply fresh air to one side of the closed room and using special equipment to exhaust air to the outside from the other side, thereby meeting the need for indoor fresh air exchange. The implementation scheme is: using low wind pressure, large flow fan, relying on mechanical force to supply air to the room from one side, and using specially designed exhaust fan to exhaust air to the outside from the other side to force the formation of a fresh air flow field in the system. At the same time of supplying air, the air entering the room is filtered, disinfected, sterilized, and oxygenated. At present, the fresh air system has been widely used in hospitals, office buildings, shopping malls, hotels, residential buildings, airports, subway stations, and high-speed rail stations. Technical problem

[0006] To overcome the above-mentioned shortcomings, the purpose of the present application is to provide a DAC and building fresh air system integrated system that can reduce the energy consumption of the DAC system, reduce the carbon dioxide concentration of the air introduced by the fresh air system, and help improve the working efficiency of the fresh air system. Technical solutions

[0007] In order to achieve the above purposes, one of the technical solutions adopted by the present application is: a DAC and building fresh air system integrated system, comprising a fresh air system group, the fresh air system group comprising a supply air system and an exhaust air system, further comprising: a DAC capture and desorption device arranged between the supply air system and the air inlet and the outlet of the exhaust air system, the DAC capture and desorption device comprising an adsorption generator and a desorption device connected in sequence, the adsorption generator being used to capture carbon dioxide, and the desorption device being used to desorb high-concentration carbon dioxide; a compressed liquefied sub-system connected with the carbon dioxide transport pipeline gas outlets of the two DAC capture and desorption devices respectively, for compressing, liquefying and storing the desorbed carbon dioxide for use.

[0008] Preferably, the supply air system comprises an air inlet unit, a supply air filter connected in sequence.

[0009] Preferably, the exhaust air system comprises an exhaust air unit, an air outlet, an exhaust air filter connected in sequence.

[0010] Preferably, the supply air filter and the exhaust air filter adopt electrostatic dust removal.

[0011] Preferably, a fresh air monitor for monitoring dust and pollutants is installed at the air outlet of the supply air filter and the exhaust air filter; an adsorption monitor for monitoring the CO2 concentration in the exhaust air is arranged at the outlet of the adsorption generator. When the filter electrode or the filter at the outlet of the adsorption generator needs to be replaced, the adsorption monitor for monitoring the CO2 concentration in the exhaust air is used to monitor the CO2 concentration in the exhaust air, and the high-concentration carbon dioxide generated by the desorption device is transported by pipeline to the nearest centralized point for centralized compression and liquefaction.

[0012] Preferably, the adsorption generator comprises an adsorption generator, and an adsorbent for capturing carbon dioxide is arranged in the adsorption generator.

[0013] Preferably, the adsorbent adopts a solid adsorbent, the solid adsorbent is grown in the form of a thin film or coated on the substrate of a porous material, a plurality of the substrates are stacked or rolled to form a filter column, and the filter column is installed inside the adsorption generator or fixed in other fixed manner in the adsorption generator; a heating device is installed on the desorption device.

[0014] Preferably, the solid adsorbent comprises alkaline particulate matter, solid amine, anion resin, MOF, HOF and COF materials, etc.

[0015] Preferably, the adsorbent adopts a liquid adsorbent, and a corrosion-resistant material is used in the interior of the adsorption generator, the interior of the desorption device and the connection therebetween, so as to reduce the corrosion of the liquid adsorbent to the equipment and pipelines; a heating device is installed on the desorption device; and the adsorbent is directly desorbed by heating.

[0016] Preferably, the liquid absorbent comprises a complex amine, an ionic liquid.

[0017] Preferably, the heating device adopts a fresh air system (building) waste heat recovery device and electric heating, maximizes energy saving, and is connected with a vacuum pump to complete the desorption step through heating and vacuumizing.

[0018] Preferably, the adsorption generator is provided with a quick-change sealing interface to facilitate the connection of the equipment and the quick replacement of the absorbent.

[0019] Preferably, the compressed liquefaction subsystem comprises a carbon dioxide conveying pipeline, a compressed liquefaction device and a carbon dioxide storage tank connected in sequence, and the carbon dioxide storage tank and the carbon dioxide conveying pipeline are respectively communicated with the desorption carbon dioxide gas outlets of the two desorbers.

[0020] Preferably, the carbon dioxide storage tank is a pressure container, and a compressor and a cooling device are connected in front of the carbon dioxide storage tank to store CO2 in liquid form in the storage tank.

[0021] Preferably, the DAC capture and desorption device and the compressed liquefaction subsystem are arranged at one location or separately constructed according to the actual site.

[0022] Preferably, a plurality of DAC capture and desorption devices form a DAC capture and desorption subsystem group, which is constructed in or near a building with a fresh air system group; and the compressed liquefaction subsystem is constructed in or near a residential area, an office building cluster or an industrial park, and is centrally arranged on the ground or underground.

[0023] The DAC and building fresh air system integrated system is applied to a building, and the building includes a residential area, an office building cluster, a subway station, a high-speed rail station, an industrial park and all buildings with a fresh air system. Advantages

[0024] The DAC and building fresh air system integrated system and the application have the advantages that the system is characterized by relying on fresh air introduced by the fresh air system to solve the key air introduction energy consumption problem of the DAC system, reduce the DAC cost, greatly reduce the carbon dioxide concentration of the air introduced by the fresh air system, help improve the working efficiency of the fresh air system, and achieve the goal of capturing carbon dioxide from the air to achieve negative carbon. BRIEF DESCRIPTION OF DRAWINGS

[0025] Fig. 1 is a system block diagram of the DAC and building fresh air system integrated system of the embodiment.

[0026] Fig. 2 is a flow chart of the DAC capture and desorber and fresh air system set of the present embodiment (bidirectional).

[0027] Fig. 3 is a system diagram of the DAC capture and desorber and fresh air system set of the present embodiment.

[0028] Fig. 4 is a schematic diagram of the DAC capture and desorber and fresh air system set of the present embodiment. Embodiment of the present application

[0029] The preferred embodiments of the present application are described in detail below with reference to the accompanying drawings, so that the advantages and features of the present application can be more easily understood by those skilled in the art, and the scope of protection of the present application can be more clearly defined.

[0030] Referring to Figs. 1-4, the present embodiment discloses a DAC and building fresh air system integrated system, comprising: a fresh air system set, the fresh air system set comprising a supply air system and an exhaust air system; a DAC capture and desorber, disposed between the supply air system and the air inlet and the outlet of the exhaust air system, the DAC capture and desorber comprising an adsorption generator and a desorber connected in sequence, the adsorption generator being used to capture carbon dioxide, and the desorber being used to desorb high-concentration carbon dioxide; and a compressed liquefied subsystem, connected with the carbon dioxide transport pipeline gas outlets of the two DAC capture and desorbers respectively, for compressing, liquefying and storing the desorbed carbon dioxide for use.

[0031] The fresh air system and the DAC system are combined, the fan of the fresh air system is directly used to supply air to the DAC system, a special air induction system is not needed, the problem of high power consumption of the DAC system and the problem of the fresh air system only circulating air without reducing carbon can be solved. In fact, the CO2 concentration in indoor places with high population density is extremely easy to exceed the standard, which brings harm to people such as chest tightness, shortness of breath, lack of concentration, and decreased judgment. The combination of the fresh air system and the DAC system takes into account the air induction problem of the DAC system, greatly reduces the carbon dioxide concentration of the inlet gas of the fresh air system, and further improves the air quality of the fresh air system. The biggest feature of the system is to rely on the air induction of the fresh air system to solve the key air induction energy consumption problem of the DAC system, while reducing the cost of the DAC, greatly reducing the carbon dioxide concentration of the air introduced by the fresh air system, which helps to improve the working efficiency of the fresh air system and achieve the goal of capturing carbon dioxide from air to achieve negative carbon.

[0032] The air supply system comprises an air inlet unit, an air supply filter connected in sequence, and the air supply filter adopts electrostatic dust removal. The air exhaust system comprises an air exhaust unit, an air exhaust outlet, and an air exhaust filter connected in sequence, and the air exhaust filter also adopts electrostatic dust removal. By using the principle of high-voltage electrostatic adsorption and electrolysis, the formaldehyde and benzene pollutants in the air are electrolyzed into carbon dioxide and water through electrodes, thereby avoiding the problem of secondary pollution, and positive and negative ions are also generated to charge the particulate matter. The collecting electrode actively adsorbs the charged particulate matter, so that the toxic gas can be removed through the two electrodes, and the dust with a size smaller than PM2.5 by 100 times can be adsorbed. More importantly, the electrodes do not need to be replaced like the filter screen, and the electrodes can be repeatedly used by being taken out and washed with water within a certain time, thereby reducing the cost and improving the purification function.

[0033] In addition, a fresh air monitor for monitoring dust and pollutants is installed at the air outlet of the air supply filter and the air exhaust filter, and an adsorption monitor for monitoring the CO2 concentration in the exhaust air is arranged at the outlet of the adsorption generator (i.e. between the desorption device and the air inlet). When the filter electrode or the filter needs to be replaced, the adsorption monitor arranged at the outlet of the adsorption generator is used to monitor the CO2 concentration in the exhaust air, and the high-concentration carbon dioxide generated by the desorption device is transported to the nearest centralized point for compression and liquefaction.

[0034] The adsorption generator comprises an adsorption generator, and an adsorbent for capturing carbon dioxide is arranged in the adsorption generator.

[0035] In some embodiments, the adsorbent is a solid adsorbent, the solid adsorbent is grown in the form of a thin film or coated on the substrate of a porous material, a plurality of substrates are stacked or rolled to form a filter column, and the filter column is installed in the adsorption generator or fixed in the adsorption generator in other fixed manners; and a heating device is installed on the desorption device. When the solid adsorbent is used, the system can still operate normally at a lower temperature, and can even adapt to extremely cold weather conditions.

[0036] The solid adsorbent includes but is not limited to alkaline particulate matter, solid amine, anion resin, MOF, HOF, COF and other materials.

[0037] In other embodiments, the adsorbent is a liquid adsorbent, and the inside of the adsorption generator, the inside of the desorption device and the connection therebetween are made of corrosion-resistant materials to reduce the corrosion of the liquid adsorbent to the equipment and pipelines; a heating device is installed on the desorption device; and the adsorbent is desorbed directly by heating. The liquid adsorbent includes composite amine and ionic liquid.

[0038] The heating device adopts a fresh air system (building) waste heat recovery device and electric heating to maximize energy saving, and the heating device is connected with a vacuum pump to complete the desorption step by heating and vacuumizing.

[0039] The adsorption generator in the embodiment is provided with a quick-change sealing interface, which can be used for replacing the adsorbent.

[0040] The compressed liquefaction subsystem in the embodiment comprises a carbon dioxide conveying pipeline, a compressed liquefaction device and a carbon dioxide storage tank connected in sequence. The carbon dioxide storage tank is in communication with the desorbed carbon dioxide gas outlets of the two desorbers. The carbon dioxide storage tank is a pressure container. A compressor and a cooling device are connected in front of the carbon dioxide storage tank, so as to liquefy and store CO2 in the storage tank.

[0041] The DAC and building fresh air system integrated system can be matched with appropriate components according to the building area and ventilation demand. The fan and the adsorption generator can be assembled and disassembled as a whole, which is convenient for quick replacement. According to the location of the building group and the surrounding buildings, the DAC capture and desorption device and the compressed liquefaction subsystem are arranged in one position or are separately constructed according to the actual site.

[0042] The DAC capture and desorption device forms a DAC capture and desorption subsystem group, which is constructed in or near the building with a new air system group; the compressed liquefaction subsystem is constructed in or near the residential area, office building group or industrial park, and is centrally arranged on the ground or underground.

[0043] Application: Embodiment 1: We introduce an innovative DAC and building fresh air integrated system, which is arranged in a residential building area with a scale of 50 buildings, each building has 10 floors, each floor has two units, and each unit has two houses. In each floor, 2 DAC and building fresh air integrated systems with 400W fans are configured, and the fresh air volume of each floor can reach 1200m 3 / h. It uses a MOF material as the main adsorbent. Outdoor gas is introduced into the air inlet of the fresh air system through the fan of the air inlet fan unit, first exchanges heat with the exhaust gas discharged from the indoor, and the condensed water is collected or discharged through the sewer. The air after heat exchange is first filtered by the air purification system (filter) to remove PM2.5 and other dust pollutants, and then performs the task of capturing carbon dioxide through the DAC system. The front end of the DAC system is a pretreatment system, which reprocesses the air treated by the filter of the fresh air system, and then adsorbs the carbon dioxide therein. The remaining fresh air is introduced into the room. According to the frequency of one air change per hour, it can realize 100m 3The fresh air flow is introduced into the room, and under the action of the fresh air system exhaust unit, the indoor air is treated by the DAC and then discharged to the outdoor. The DAC system uses MOF polymer nanocomposite as absorbent, which is coated on the porous material with heating, and performs adsorption and desorption at the front end of the fresh air system air inlet and exhaust port. The two adsorption and desorption devices are operated intermittently. After a period of adsorption, the adsorption and desorption device is desorbed by electric heating and vacuum pump to the carbon dioxide in the adsorption generator, and the desorbed carbon dioxide is transported to the compression and liquefaction treatment device for storage, while the other adsorption generator continues to absorb the pretreated air. The adsorption and desorption occur in the same device, and the adsorption generator also serves as a desorber. The carbon dioxide concentration of the indoor air is reduced to below 80 ppm. This system can capture 2635.8 tons of carbon dioxide per year in the whole process in a residential area with a building area of 200,000 square meters, with a carbon capture amount of 744 kg / a per capita, which is basically equivalent to the annual per capita carbon emissions, and the carbon capture amount per unit area is 22 kg / (m2·a), which is 20.9% lower in energy consumption compared with direct air capture using fresh air system fan units. At the same time, the efficiency of the fresh air system is improved and the energy consumption of the DAC system is reduced.

[0044] The application of a DAC and building fresh air system integrated system, the DAC and building fresh air system integrated system adopts the DAC and building fresh air system integrated system described above, and is applied to a building, the building includes a residential area, an office building cluster, a subway station, a high-speed rail station, an industrial park and all buildings with a fresh air system.

[0045] Example 2: A DAC and fresh air integrated system using ionic liquid and MOF as adsorbent is installed in a building area of 100,000 square meters of office building cluster. The office building cluster has ten buildings, each building has 10 floors, the floor height is 2.8 meters, the single floor area is 1000 square meters, the active population is 7200 people, and 800 1500m 3 / h air volume fans and 300L of ionic liquid are provided. The outdoor air is treated by the fresh air system, enters the filter, and then enters the adsorption generator. The adsorption generator uses MOF polymer material coated on the porous material with heating as adsorbent, separates carbon dioxide from air by adsorption at normal pressure and temperature and desorption at low pressure and high temperature, and the purified air enters the indoor room to meet the indoor 72m 3The low carbon dioxide concentration fresh air requirement of / (h·person) is discharged to an exhaust port by a fresh air exhaust unit after the indoor air is circulated for one cycle, and the filter is connected to the exhaust port to remove the dust therefrom, and then the indoor exhaust air enters an exhaust adsorption generator using ionic liquid as an adsorbent to perform adsorption and desorption, the adsorption generator of the ionic liquid adsorbent is a horizontal structure, which can greatly reduce the space occupation, the indoor exhaust air is sprayed and adsorbed by the ionic liquid in multiple stages, and the carbon dioxide with increased concentration is separated and recovered from the air again, the air is discharged to the outdoor, and the carbon dioxide is compressed and stored for utilization through a recovery pipeline. Under the condition of 8 hours of working time and 330 days of working days, the office area can capture 1667.8 tons of carbon dioxide per year, the carbon capture amount per person is 232 kg, and the carbon capture amount per unit area is 16.5 kg / m 2 Compared with direct air capture, the use of a fresh air system fan unit can save energy by 30.1%. Industrial applicability

[0046] The above embodiments are only for illustrating the technical concept and characteristics of the present application, the purpose is to enable the person skilled in the art to understand the content of the present application and implement it, and cannot limit the protection scope of the present application, any equivalent changes or modifications made according to the spirit and essence of the present application should be covered within the protection scope of the present application.

Claims

1. An integrated DAC and building fresh air system, comprising a fresh air system group, wherein the fresh air system group includes a supply air system and an exhaust air system, characterized in that: Also includes: A DAC trap and desorber is disposed between the air supply system and the air inlet and at the outlet of the air exhaust system. The DAC trap and desorber includes an adsorption generator and a desorber connected in sequence. The adsorption generator is used to trap carbon dioxide, and the desorber is used to desorb and generate high-concentration carbon dioxide. The compression-liquefaction subsystem is connected to the gas outlet of the carbon dioxide transport pipeline of each of the two DAC traps and desorbers, and is used to compress, liquefy and store the desorbed carbon dioxide.

2. The integrated DAC and building fresh air system according to claim 1, characterized in that: The air supply system includes an air intake unit and an air supply filter connected in sequence.

3. The integrated DAC and building fresh air system according to claim 2, characterized in that: The exhaust system includes an exhaust unit, an exhaust outlet, and an exhaust filter connected in sequence.

4. The integrated DAC and building fresh air system according to claim 3, characterized in that: The air supply filter and exhaust filter are equipped with electrostatic dust removal.

5. The integrated DAC and building fresh air system according to claim 3, characterized in that: The supply air filter and exhaust air filter are equipped with fresh air monitors for monitoring dust and pollutants at their outlets; the adsorption generator outlet is equipped with an adsorption monitor for monitoring the CO2 concentration in the exhaust air.

6. The integrated DAC and building fresh air system according to claim 1, characterized in that: The adsorption generator includes an adsorption generator, and the adsorption generator is provided with an adsorbent for carbon dioxide capture.

7. The integrated DAC and building fresh air system according to claim 6, characterized in that: The adsorbent is a solid adsorbent, which is grown or coated on a porous material substrate in the form of a thin film. Multiple substrates are stacked or rolled up to form a filter column, which is installed inside the adsorption generator or fixed in the adsorption generator in other ways. The desorber is equipped with a heating device.

8. The integrated DAC and building fresh air system according to claim 7, characterized in that: The solid adsorbents include alkaline particulate matter, solid amines, anion exchange resins, MOF, HOF, and COF materials.

9. The integrated DAC and building fresh air system according to claim 6, characterized in that: The adsorbent is a liquid adsorbent, and the interior of the adsorption generator, the interior of the desorber, and their connections are made of corrosion-resistant materials. The desorber is equipped with a heating device.

10. The integrated DAC and building fresh air system according to claim 6, characterized in that: The liquid adsorbent includes complex amines and ionic liquids.

11. The integrated DAC and building fresh air system according to claim 7 or 9, characterized in that: The heating device uses a waste heat recovery device from the fresh air system and electric heating, and is connected to a vacuum pump.

12. The integrated DAC and building fresh air system according to claim 6, characterized in that: The adsorption generator is equipped with a quick-change sealing interface.

13. The integrated DAC and building fresh air system according to claim 1, characterized in that: The compression liquefaction subsystem includes a carbon dioxide delivery pipeline, a compression liquefaction device, and a carbon dioxide storage tank connected in sequence. The carbon dioxide storage tank and the carbon dioxide delivery pipeline are respectively connected to the desorbed carbon dioxide gas outlets of two desorbers.

14. The integrated DAC and building fresh air system according to claim 12, characterized in that: The carbon dioxide storage tank is a pressure vessel, and a compressor and a cooling device are connected to the front of the carbon dioxide storage tank.

15. The integrated DAC and building fresh air system according to claim 1, characterized in that: The DAC capture and desorber and the compression liquefaction subsystem are located in one place or constructed separately depending on the actual site.

16. The integrated DAC and building fresh air system according to claim 14, characterized in that: Multiple DAC traps and desorbers form a DAC trapping and desorption subsystem group, which is built in or near a building with a fresh air system group; the compression and liquefaction subsystem is built in a residential area, office building cluster or nearby industrial park, and is centrally located above ground or underground.

17. An application of an integrated DAC and building fresh air system, characterized in that: The integrated DAC and building fresh air system adopts the integrated DAC and building fresh air system as described in any one of claims 1-16, and is applied to buildings, including residential communities, office building clusters, subway stations, and high-speed rail stations.

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