Direct air trapping device and method based on solid adsorbent and fused with focused solar heat collection technology

Abstract

The invention discloses a solid adsorbent-based direct air trapping device and method fused with a focused solar heat collection technology. Comprising the following steps: air enters a reactor containing a foamed nickel loaded Bi2O3 nano material, adsorption is completed at the temperature of 100 DEG C, and the adsorption condition is detected through a CO2 analyzer; heating to 400 DEG C, and decomposing to generate CO2, wherein the concentration of the CO2 generated by decomposition is greater than 90%; and the CO2 is stored in the CO2 storage tank after passing through the compressor. The CO2 trapping device and method provided by the embodiment of the invention have the advantages of obvious energy-saving advantage, no pollution, simplicity in operation, wide raw material source and capability of generating high-added-value products.

Description

Technical Field

[0001] The present invention relates to the field of carbon dioxide capture technology, and in particular to a direct air capture device and method based on solid adsorbents that integrates focused solar thermal collection technology. Background Art

[0002] In recent years, global CO2 emissions have increased year by year. The CO2 concentration in the atmosphere has increased from about 310ppm in 1960 to 420ppm in 2024. Currently, global CO2 emissions exceed 35 billion tons per year. The large amount of greenhouse gases emitted, led by carbon dioxide, has caused serious problems such as global warming.

[0003] Carbon capture is a critical step in carbon capture, storage and utilization (CCUS) technology. At present, the methods that can effectively achieve carbon capture are divided into CCS technology for fixed emission sources and direct air capture DAC technology. Compared with CCS technology, DAC technology requires higher energy consumption and cost due to the lower concentration of captured CO2. Since Professor Lackner proposed DAC technology in 1999, it has been in its early stages for more than 20 years.

[0004] At present, DAC technology includes alkaline hydroxide solution DAC technology, amine solution DAC technology, amino acid solution / BIGs technology, solid amine adsorbent DAC technology, MOFs material DAC technology, and variable humidity adsorption technology. The DAC technology currently used in industry on a large scale is mainly alkaline hydroxide DAC technology, which absorbs CO2 through KOH or NaOH and converts it into Na2CO3, then adds Ca(OH)2 to generate precipitated CaCO3, and finally decomposes at high temperature to produce CO2 and CaO. In the entire DAC technology, the adsorbent can be recycled.

[0005] CN 116492811 A proposes a focused solar heating air carbon capture system and method, which uses solar energy concentration to complete the adsorption and desorption of CO2, effectively reducing the energy consumption of air capture, but the method cannot be used at night or when there is insufficient sunlight. CN 118079591 A proposes a direct air capture system and method based on alkali metal-based solid adsorbents that integrates concentrated solar energy thermal power generation technology. The method effectively utilizes the waste heat inside the system and further improves the effective utilization of heat. However, the method can only be used for materials with lower decomposition temperatures. At the same time, the method converts solar energy into thermal energy, thermal energy into electrical energy, and electrical energy into thermal energy. There is a large amount of energy loss in the entire energy conversion process, resulting in insufficient solar energy utilization.

[0006] In summary, the current direct air capture CO2 technology has high energy consumption, and some DAC technologies have environmental pollution. In view of this, developing a green, low-energy, and efficient CO2 capture technology has become a new development direction. Summary of the invention

[0007] The purpose of the present invention is to provide a zero-energy, green air capture carbon dioxide method and device to address the problems of high energy consumption of existing DAC technology process systems and environmental pollution caused by some DAC technologies. The present invention adopts the following technical solutions:

[0008] In order to achieve the above-mentioned purpose, in the first aspect, the present invention provides a method for using nickel foam loaded nano-Bi2O3 materials to directly capture carbon dioxide from air using solar energy, and the method is implemented in the carbon dioxide air capture device described in the second aspect of the present invention. The method comprises: under the continuous energy supply of solar energy or a heat storage device, air containing carbon dioxide is introduced into the Bi2O3 CO2 capture device using an air generator to carry out a CO2 adsorption reaction, and after the adsorption is completed, the lean CO2 gas is discharged into the air. Then, the temperature of the reactor is increased to realize the desorption reaction of CO2, and the CO2 obtained after desorption is stored in a storage tank after passing through a compressor. Through the method of using the present invention, It can capture CO2 from the air with zero energy consumption.

[0009] In the second aspect, the present invention provides a direct air capture device based on solid adsorption and fusion focusing solar thermal collection technology, which is used in conjunction with the Bi2O3 direct air capture CO2 method described in the first aspect, and the device mainly includes:

[0010] The solar energy concentration and heat storage system stores heat through a solar energy concentration device to ensure that energy is provided to the system for 24 hours. At the same time, under the action of the insulation layer, the heat source is evenly dispersed and supplied to the reactor for reaction, so that the entire system can continuously capture CO2.

[0011] The reactor is an experimental chamber for Bi2O3 adsorption and desorption. The process of capturing CO2 by bismuth oxide includes two parts. The first step is to convert CO2 in the air into Bi2O2CO3: CO2(g)+Bi2O3(s)→Bi2O2CO3(s). The second step is to heat the reaction chamber to 400°C to decompose Bi2O2CO3. The decomposition reaction is: Bi2O2CO3(s) →CO2(g)+Bi2O3(s).

[0012] The vacuum pump is used to remove the remaining impurity gases from the reaction chamber after the system completes the CO2 adsorption, so as to ensure that high-purity CO2 can be collected after desorption.

[0013] The compressor mainly increases the pressure of the CO2 produced after decomposition to ensure that the CO2 can enter the CO2 storage tank.

[0014] The CO2 storage tank mainly stores CO2 pressurized by a compressor.

[0015] The beneficial effects of the present invention are as follows: the present invention utilizes porous nickel foam loaded nano Bi2O3 as an adsorbent material to complete the adsorption and desorption process of CO2 in a reaction device, and uses solid nano materials as adsorbents. Under the premise of excellent capture, the step of liquid-solid separation can be avoided, the capture time can be reduced, and the number of CO2 cycle captures can be increased, thereby increasing the capture amount. The energy source for heating in the present invention is solar energy. As the most widely used new energy source, with the cooperation of a solar concentrator and a heat storage device, it can continuously and stably provide the required energy consumption for the entire system, ensure that CO2 capture can be carried out uninterruptedly, and realize zero energy consumption and efficient capture of CO2. The reactor is provided with porous quartz baffles on the top and bottom to prevent the adsorbent from floating up and down under the action of airflow. At the same time, the porous structure of the baffle is conducive to the uniform dispersion of the gas, so that CO2 can fully contact with the adsorbent, increase the contact area, and thus accelerate the reaction. The thermal insulation layer fixes the reactor and can play a role in heat preservation and shock absorption. The present invention realizes zero-energy direct air capture of CO2, thereby reducing the CO2 concentration in the air and slowing down the rate of global warming. The captured CO2 is also widely used in the fields of geology, chemical engineering and biology, and has extremely high economic value and environmental utilization value. In addition, the method has no special requirements and restrictions on the source, composition and environment of the gas, and is therefore universal for CO2 capture. Based on the above, the present invention has good application prospects. Compared with the existing DAC technology, this method has the following advantages:

[0016] The present invention provides a novel nano material (nickel foam loaded with bismuth oxide) and method (solar concentrated light energy supply) for direct air capture of CO2, which can simultaneously meet the requirements of adsorption and desorption.

[0017] The nickel foam of the present invention has a high specific surface area and a porous structure, which can load a large amount of bismuth oxide, increase the dispersibility of bismuth oxide, increase the contact area between bismuth oxide and air, and accelerate the adsorption rate. It also has a porous structure that can directly adsorb CO2, increasing the adsorption amount of CO2;

[0018] The nickel foam of the present invention loads Bi2O3 and also has good thermal stability and chemical stability;

[0019] The nickel foam and bismuth oxide of the present invention are both green materials and will not cause environmental pollution during the adsorption and desorption process;

[0020] The energy consumption of the adsorption and desorption processes of the present invention is provided by solar energy, thus avoiding the high energy consumption problem in the direct air capture of CO2 process.

[0021] The adsorption and desorption of the present invention can be operated continuously for 24 hours.

[0022] The method of the present invention has the advantages of simple preparation process, low cost, no solvent loss, no corrosion to equipment, zero energy consumption, continuous operation, and obvious cost advantage.

[0023] In summary, the present invention has a simple process, obvious energy-saving advantages, no pollution, a wide range of raw material sources and can generate high value-added products. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 It is a schematic diagram of the reaction device of the present invention;

[0026] Figure 2 It is a top view of the reactor of the present invention.

[0027] Description of the drawings: Air generator—1, steam generator—2, air intake valve—3, drying tube—4, flow meter—5, flow meter—6, air intake valve—7, heat storage device central control center—8, heat exchange device—9, liquid outlet valve—10, probe display stand—11, probe—12, high temperature heat storage tank—13, probe display stand—14, probe—15, low temperature heat storage tank—16, thermal liquid pump—17, solar tracker—18, collector—19, reflector 1—20, reactor—23, reflector 4—24, vacuum pump—27, air outlet valve—28, air outlet valve—29, carbon dioxide infrared analyzer—30, stop valve—31, flow meter—32, sensor—33, back pressure valve—34, compressor—35, storage tank—36. The reactor includes a probe display platform 21, a probe 22, a stainless steel and insulation layer 25, a porous quartz plate 26, a circulating water circuit 37, a reaction chamber 38, a stage 39, a fixing device 40, and a dome 41. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] like Figure 1 As shown, the present invention provides a technical solution: a direct air capture device and method based on solid adsorbents that integrates focusing solar thermal collection technology. The method provided by the present invention is divided into two steps. The first step is to complete the adsorption of CO2 by Bi2O3 nanomaterials in the reactor and generate Bi2O2CO3: CO2(g)+Bi2O3(s) →Bi2O2CO3(s), called the adsorption process; the second step completes the decomposition of Bi2O2CO3: Bi2O2CO3(s)→CO2(g)+Bi2O3(s), which is called the desorption process. The device system of the whole reaction process includes: the air generator 1 and the steam generator 2 respectively use the flowmeter 5 and the flowmeter 6 to let the air and steam enter the reactor from the porous quartz plate 26 at the bottom of the reactor at a certain flow rate. At the same time, in order to increase the adsorption rate, the reflector 24 is used to focus or the heat storage device central control center 8 is used to power the system, increase the temperature of the reactor 23, and the carbon dioxide infrared analyzer 30 is used to monitor the adsorption process in real time. After the carbon dioxide infrared analyzer 30 detects that CO2 is consistent with the air, the adsorption reaction is completed. After the adsorption is completed, the system air is evacuated through the vacuum pump 27, and then the reactor temperature is increased through the reflector 24 focusing or the heat storage device central control center 8. At the same time, the probe 21 is used to monitor the temperature, pressure and humidity of the reactor during the desorption process, and displayed on the probe display station 22. Finally, the desorbed CO2 is pressurized by the compressor 35 and stored in the CO2 storage tank 36.

[0030] The function of the air generator 1 is to compress the air and allow it to enter the reactor through the flow meter 5.

[0031] The function of the steam generator 2 is to gasify water to form water vapor and allow it to enter the reactor through the flow meter 6.

[0032] The function of the heat exchanger 9 is to exchange the heat in the molten salt to the insulation layer 25 to ensure that the adsorption and desorption processes in the reactor proceed normally.

[0033] The function of the probes 12, 15, 22 is to independently monitor the real-time temperature, humidity and pressure in the high-temperature storage tank, the low-temperature storage tank and the reaction chamber, and adjust the temperature, humidity and pressure in the reaction chamber through the probe display consoles 11, 14, 21. At the same time, the console 21 is equipped with a gas chromatograph, and the gas is extracted into the gas chromatograph by the probe needle in the internal pipeline of the probe, and real-time qualitative and quantitative detection and analysis are performed together with the CO2 infrared analyzer.

[0034] The function of the collector is to capture solar radiation energy and convert it into heat energy, which is then transferred to a heat medium (such as molten salt) to increase the temperature of the heat medium. This process is the basis for solar thermal storage devices to achieve heat collection and storage.

[0035] The function of the reflector 20 is that the reflector can significantly increase the focusing degree of light, effectively concentrate the solar radiation energy onto a small area, and finally be absorbed by the collector 19. Secondly, the sunlight is reflected to the reflector 24 for the next step of focusing.

[0036] The function of the reflector 24 is to further focus the light reflected by the reflector 20 and reflect it to the surface of the reactor to complete the heating of the reactor and ensure the adsorption and desorption process during the day.

[0037] The function of the solar tracker 18 is to automatically track the position of the sun. Ensuring that the solar concentrating device is always facing the sun can maximize the absorption of sunlight and improve the efficiency of solar energy collection.

[0038] The inlet valves 3, 7, the outlet valves 28, 29, and the gas flow routes for controlling the closing and circulating parts of the entire system are used to achieve different stages of the reaction, and the four valves can be independently controlled.

[0039] The reactor 23 is an experimental chamber for adsorption and decomposition. The first step is to convert CO2 in the air into Bi2O2CO3: CO2(g)+Bi2O3(s)→Bi2O2CO3(s). The second step is to heat the Bi2O2CO3 obtained in the first step through a heat storage device. Bi2O2CO3 is converted into CO2 and Bi2O3: Bi2O2CO3(s)→CO2(g)+Bi2O3(s). Probe display table 21, probe 22, stainless steel and heat preservation 25, porous quartz plate 26, circulating water circuit 37, reaction chamber 38, stage 39, fixing device 40, dome 41.

[0040] The main function of the porous quartz plate 26 is to fix the position of the adsorbent in the experimental chamber to prevent the adsorbent from floating up and down under the action of the airflow. At the same time, the porous structure of the baffle is conducive to the uniform dispersion of the gas, so that CO2 can fully contact with the adsorbent, increase the contact area, and thus accelerate the reaction.

[0041] The vacuum pump 27 is used to exhaust the impurity gas in the reactor to ensure the concentration of CO2 entering the CO2 storage tank.

[0042] The main function of the carbon dioxide infrared analyzer 30 is to monitor the process of adsorption and desorption of CO2 by the adsorbent in real time to ensure that the adsorption and desorption can be smoothly connected.

[0043] The back pressure valve 34 is used to keep the pressure at the pump outlet constant to prevent damage to the system due to pressure fluctuations. At the same time, by adjusting the opening of the valve, the pressure in the pipeline can be kept within a certain range, thereby effectively preventing the occurrence of backflow.

[0044] The compressor 35 and the CO2 storage tank 36 are used to pressurize the decomposed CO2 and then collect it.

[0045] The function of the circulating water circuit 37 is to lower the temperature of other parts of the reactor to ensure that the remaining components can operate normally.

[0046] The function of the fixing device 40 is to fix the dome to ensure that the reactor is in a sealed state, and the material of the fixing device 40 is stainless steel.

[0047] The dome 41 is used to seal the reactor and receive the heat from the reflector 24. The dome 41 is made of quartz.

[0048] Example 1 (Daytime CO2 Capture)

[0049] use Figure 1 The DAC capture reaction device shown in the figure has the following specific steps:

[0050] First, 2 cm × 2 cm nickel foam was placed in deionized water and anhydrous ethanol for 15 min respectively, and then taken out and dried for use to remove surface dirt.

[0051] Further, 1 g of Bi2O3 was weighed into a beaker, and then 200 ml of deionized water solution was added, and ultrasonicated for 15 min to uniformly disperse the Bi2O3 in the deionized water.

[0052] The dried nickel foam was further placed in a Bi2O3 aqueous solution and ultrasonicated for 15 minutes, and then placed in a 150°C oven and kept warm for 1 hour.

[0053] Furthermore, the nickel foam is taken out and placed in a 400°C furnace for calcination for 30 minutes, so that it is loaded with high-purity Bi2O3.

[0054] Furthermore, the calcined adsorbent is placed in a reactor, and the air generator 1, the steam generator 2, and the air inlet valve 3, 7 are opened.

[0055] Furthermore, the reactor is placed directly below the reflector 24 after focusing. This allowed the temperature of the reactor to be maintained at 100°C.

[0056] Furthermore, the flow meter 5 is set to 1500 mL / min to allow air to enter the reactor to complete the adsorption reaction.

[0057] Furthermore, the pressure, temperature and humidity in the reaction chamber are monitored in real time by the probe 22 , and the probe display station 21 displays the temperature, pressure and humidity in real time.

[0058] Further, the outlet valves 28 and 29 are opened, and the CO2 concentration is detected by the CO2 analyzer 30. When the CO2 concentration of the gas passing through the outlet valve 29 is equal to and remains unchanged with that in the air, the adsorption is completed, and the inlet valves 3 and 7 and the outlet valves 28 and 29 are closed.

[0059] Furthermore, the vacuum pump 27 is turned on to exhaust the air from the reaction chamber 23 .

[0060] Furthermore, the focusing power of the reflector was increased, so that the temperature of the reactor was raised to 400°C and kept running stably for 1 hour.

[0061] Furthermore, the temperature in the reactor 23 is stably maintained at 400° C., the outlet valve 29 is opened, and the CO2 concentration and desorption amount are detected by a CO2 infrared analyzer and a gas chromatograph. When CO2 appears, the outlet valve 29 is closed, the outlet stop valve 31 and the back pressure valve 33 are opened, and the CO2 is collected into the CO2 storage tank 21 through the flow meter 32.

[0062] Results: The carbon dioxide capture process in this example is to complete the adsorption after air is introduced into the room temperature for 2 hours, and the obtained Bi2O2CO3 is decomposed for 1 hour. After calculation, the capture amount of CO2 in the product gas is 2.00mmol g -1， , its CO2 concentration is >90%.

[0063] Example 2 (CO2 capture at night)

[0064] use Figure 1 The DAC capture reaction device shown in the figure has the following specific steps:

[0065] According to the steps of Example 1, a foamed nickel / Bi2O3 composite material was synthesized.

[0066] Furthermore, during the day, the binary molten salt (sodium chloride: Potassium chloride = 1:1) is introduced into the collector, which absorbs solar energy and converts it into thermal energy, and finally stored in a high-temperature storage tank.

[0067] Furthermore, the calcined adsorbent is placed in a reactor, and the air generator 1, the steam generator 2, and the air inlet valve 3, 7 are opened.

[0068] Furthermore, the liquid outlet valve 10 is opened to discharge the molten salt in the high-temperature storage tank, and the heat is introduced into the insulation layer 25 through the heat exchange device 9 and the heat storage device control center 8 to keep the temperature of the reactor at 100°C.

[0069] Furthermore, the flow meter 5 is set to 1500 mL / min to allow air to enter the reactor to complete the adsorption reaction.

[0070] Furthermore, the pressure, temperature and humidity in the reaction chamber are monitored in real time by the probe 22 , and the probe display station 21 displays the temperature, pressure and humidity in real time.

[0071] Further, the outlet valves 28 and 29 are opened, and the CO2 concentration is detected by the CO2 analyzer 30. When the CO2 concentration of the gas passing through the outlet valve 29 is equal to and remains unchanged with that in the air, the adsorption is completed, and the inlet valves 3 and 7 and the outlet valves 28 and 29 are closed.

[0072] Furthermore, the vacuum pump 27 is turned on to exhaust the air from the reaction chamber 23 .

[0073] Furthermore, the temperature of the reactor is raised to 400° C. through the heat exchange device 9 and the heat storage device control center 8 and maintained in stable operation for 1 hour.

[0074] Furthermore, the temperature in the reactor 23 is stably maintained at 400° C., the outlet valve 29 is opened, and the CO2 concentration and desorption amount are detected by a CO2 infrared analyzer and a gas chromatograph. When CO2 appears, the outlet valve 29 is closed, the outlet stop valve 31 and the back pressure valve 33 are opened, and the CO2 is collected into the CO2 storage tank 21 through the flow meter 32.

[0075] Results: The carbon dioxide capture process in this example was to complete the adsorption after air was introduced into the room temperature for 2 hours, and the obtained Bi2O2CO3 was decomposed for 1 hour. After calculation, the capture amount of CO2 in the product gas was 2.02mmol g -1， , its CO2 concentration is >90%.

[0076] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A direct air capture device and method based on solid adsorbent integrating focusing solar thermal collection technology, characterized in that: The device comprises: an air generator-1, a steam generator-2, an air intake valve-3, a drying tube-4, a flow meter-5, a flow meter-6, an air intake valve-7, a heat storage device central control center-8, a heat exchange device-9, a liquid outlet valve-10, a probe display stand-11, a probe-12, a high-temperature heat storage tank-13, a probe display stand-14, a probe-15, a low-temperature heat storage tank-16, a heat transfer liquid pump-17, a solar tracker-18, a collector- 19. Reflector 1-20, probe display stand-21, probe-22, reactor-23, reflector 4-24, stainless steel and insulation layer-25, porous quartz plate-26, vacuum pump-27, air outlet valve-28, air outlet valve-29, carbon dioxide infrared analyzer-30, stop valve-31, flow meter-32, sensor-33, back pressure valve-34, compressor-35, storage tank-36, and all parts are made of anti-corrosion materials.

2. A direct air capture device and method based on solid adsorbents in fusion focusing solar thermal technology according to claim 1, characterized in that: The adsorption material is a foamed nickel loaded nano-Bi2O3 material.

3. A direct air capture device and method based on solid adsorbents in fusion focusing solar thermal technology according to claim 2, characterized in that: The nickel foam is placed in a Bi2O3 aqueous solution for ultrasonication, baking and calcination.

4. A direct air capture device and method based on solid adsorbents in fusion focusing solar thermal technology according to claim 3, characterized in that: The ultrasonic time is 15 minutes; the baking temperature is 150° C. and the temperature is kept for 1 hour; the calcination temperature and time are 400° C. and 30 minutes respectively.

5. A direct air capture device and method based on solid adsorbents in fusion focusing solar thermal technology according to claim 1, characterized in that: The first step in the two-step method is the adsorption process, which is to pass air (CO2 volume concentration 420ppm) into the reactor and complete the adsorption at 100°C and normal pressure. The adsorption reaction is: CO2(g)+Bi2O3(s)→Bi2O2CO3(s).

6. A direct air capture device and method based on solid adsorbents in fusion focusing solar thermal technology according to claim 1, characterized in that: The second step of the two-step method is a desorption process, in which Bi2O2CO3 is heated to 400°C in a reaction chamber for decomposition reaction, the CO2 product gas CO2 volume concentration is greater than 90%, and the decomposition reaction is: Bi2O2CO3(s)→CO2(g)+Bi2O3(s).

7. A direct air capture device and method based on solid adsorbents in fusion focusing solar thermal technology according to claim 1, characterized in that: The molten salt is a mixed chloride salt, and the mixed chloride molten salt can be one or more of sodium chloride, potassium chloride, calcium chloride, zinc chloride, and magnesium chloride.

8. The direct air capture device and method based on solid adsorbents in fusion focusing solar thermal technology according to claim 1, characterized in that: The described fusion focusing solar thermal collection technology is based on solid adsorption and a direct air capture device comprising an air intake system, a reaction system, a focusing and heat storage system, a detection system and a storage system.

9. A direct air capture device and method based on solid adsorbents in fusion focusing solar thermal technology according to claim 8, characterized in that: The energy consumption of the reaction system is provided by the solar energy converted by the concentration and heat storage system.

10. A direct air capture device and method based on solid adsorbents in fusion focusing solar thermal technology according to claim 8, characterized in that: The reaction system includes a probe display platform 21 , a probe 22 , a stainless steel and heat-insulating layer 25 , a porous quartz plate 26 , a circulating water circuit 37 , a reaction chamber 38 , a stage 39 , a fixing device 40 , and a dome 41 .

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