Microreactor for conversion of carbon dioxide in air

Abstract

The application discloses a kind of microreactor for carbon dioxide conversion in air, including reaction cavity, and reaction cavity shell is made of light transmission glass;Multiple sets of catalyst carrier assemblies are equipped in reaction cavity cavity, along material flow direction, adjacent catalyst carrier assemblies are staggered in turn and form baffle passage;Each set of catalyst carrier assembly is composed of transversely arranged catalyst carrier and longitudinally arranged catalyst carrier;Catalyst carrier is foam ceramic carrier, and catalyst is loaded on carrier, and foam ceramic carrier is porous structure.The application limits reactor, can realize CO2 on foam ceramic carrier in reactor inside sufficient mass transfer and heat transfer, and transversely and longitudinally arranged carrier can increase the residence time of CO2 in foam ceramic pore, and transversely and longitudinally arranged carrier can expose more active sites of catalyst, so that the catalytic efficiency of entire reaction is improved, realizes CO2 100% conversion rate, and also can realize 100% conversion of CO2 in air.

Description

Technical Field

[0001] This invention relates to a microreactor for the conversion of carbon dioxide in the air. Background Technology

[0002] The resource-based conversion of carbon dioxide using catalytic reduction technology is a key technology for realizing the natural "carbon cycle" and alleviating the numerous environmental problems caused by excessive carbon dioxide emissions. Currently, research on photocatalysts, thermal catalysts, and electrocatalysts for carbon dioxide is becoming increasingly mature, while research on catalyst supports and reactors is still in its early stages. Reforms and innovations in reactor structure, mass transfer characteristics, and catalyst matching are indispensable for transforming the catalytic reduction of carbon dioxide from the laboratory stage to industrial applications. Currently, microreactors are classified in various ways. For example, based on different operating modes, microreactors can be divided into three main categories: batch microreactors, semi-continuous microreactors, and continuous microreactors. Based on the different applications of microreactors, they can also be divided into two main categories: experimental microreactors and production microreactors. Furthermore, based on the type of microstructure, microreactors can be classified into capillary microreactors, micropore array reactors, microchannel reactors, and membrane dispersion microreactors. Among these, microchannel reactors are the most widely used.

[0003] Currently, methods for the catalytic reduction of carbon dioxide mainly focus on electrochemical catalysis, thermochemical catalysis, and photochemical catalysis. Electrochemical catalysis (Energy & Environmental Science. 2023, DOI: https: / / doi.org / 10.1039 / d2ee03752a) is currently focusing on the integrated design of catalysts on gas diffusion electrodes. By combining copper-based catalysts, it can operate at high currents and achieve high selectivity and less poisoning. Photochemical catalysis (ACS Catalysis. 2023, 13, 3618-3626) primarily utilizes traditional photocatalytic reactors, which has limitations in continuously converting photocatalytic efficiency. Recent research on thermochemical catalysis (Energy & Environmental Science. 2022, 15, 595) demonstrates the excellent catalytic reductive properties of liquid metals, enabling the thermal reduction of carbon dioxide to solid carbon. The main reaction device is a bubbling reactor, but the energy transfer between carbon dioxide and the catalyst during the catalytic process is somewhat limited. Summary of the Invention

[0004] Purpose of the invention: The purpose of this invention is to provide a microreactor for the conversion of carbon dioxide in air, which has high mass and heat transfer efficiency, thereby improving the conversion efficiency of CO2 in catalytic reactions.

[0005] Technical Solution: The microreactor for converting carbon dioxide in air according to the present invention includes a reaction chamber, the shell of which is made of transparent glass; multiple sets of catalyst carrier assemblies are provided inside the reaction chamber, and adjacent catalyst carrier assemblies are arranged alternately along the material flow direction to form a baffle channel; each set of catalyst carrier assemblies consists of an integrally formed horizontally arranged catalyst carrier and a vertically arranged catalyst carrier; the catalyst carrier is a foam ceramic catalyst carrier, and a catalyst is loaded on the catalyst carrier, wherein the foam ceramic catalyst carrier is a porous foam ceramic catalyst carrier.

[0006] The light-transmitting glass is optical high-temperature resistant glass, which has excellent light transmittance in the ultraviolet to infrared bands and can withstand high temperatures of 1200℃ for a long time; the inner diameter of the reaction chamber is 3cm, the height of the reaction chamber is 20cm, and the wall thickness of the reaction chamber is 0.3mm.

[0007] The catalyst is either a photocatalyst In2O3 / TiO2 or a thermal catalyst liquid metal GaIn.

[0008] The pore size of the foam ceramic catalyst support is 20 to 250 micrometers.

[0009] The reaction chamber has a slot for a foam ceramic catalyst carrier on its inner wall. The horizontally arranged catalyst carrier is arc-shaped and is embedded in the slot to fit and connect with the inner wall of the reaction chamber. The vertically arranged catalyst carrier is rectangular. In each catalyst carrier assembly, the vertically arranged catalyst carrier and the horizontally arranged catalyst carrier are integrally formed.

[0010] Inside the reactor, horizontally and vertically arranged catalyst supports block the vertical diffusion of carbon dioxide. By continuously changing the diffusion direction of carbon dioxide, the residence time of carbon dioxide inside the reactor is increased, which is beneficial to the catalytic reaction and the maximization of energy exchange and utilization.

[0011] The reaction chamber is equipped with a material inlet, a solid product outlet, a thermometer socket, and a gas outlet. The material inlet and the solid product outlet are located at the bottom of the reaction chamber, while the thermometer sensor socket and the gas outlet are located at the top of the reaction chamber.

[0012] The reactor also includes a light source, which is arranged around the outside of the reaction chamber, and the irradiation area of ​​the light source is the same length as the reaction chamber.

[0013] The reactor further includes a secondary condenser I, a secondary condenser II, a reflux tank, and a reboiler. An external gas source is connected to the material inlet at the bottom of the reaction chamber via an inlet pipe. The outlet of the reboiler is also connected to the material inlet at the bottom of the reaction chamber. The gas outlet at the top of the reaction chamber is connected to the secondary condenser I. The liquid outlet of the secondary condenser I is connected to the inlet of the reboiler. The gas outlet of the secondary condenser I is connected to the inlet of the secondary condenser II. The liquid outlet of the secondary condenser II is connected to the reflux tank. The gas outlet of the secondary condenser II is connected to the inlet pipe.

[0014] The air intake pipe is also equipped with a gas flow meter.

[0015] The reactor also includes an online gas chromatograph, which is used to detect the composition of the gas in the condenser I.

[0016] The gas outlet at the top of the reaction chamber is connected to condenser I, which condenses and separates the water vapor in the mixed gas. Condenser I then sends the gas after gas-liquid separation to condenser II, which separates the low-boiling-point substances from the product and sends them to the reflux tank. The separated gas is then sent to the inlet pipe and re-enters the reaction chamber for reaction. Condenser I sends the water after gas-liquid separation to the reboiler via a peristaltic pump, and the water vapor condensate is then pumped into the reboiler for reuse.

[0017] The confined reaction of this invention refers to the use of transverse and longitudinal catalyst supports within the reactor cavity to obstruct the vertical diffusion direction of carbon dioxide, effectively retaining CO2 within the pores of the foam ceramic. The catalyst and the retained CO2 undergo a catalytic reaction within this confined space. This confined space effectively prevents direct contact between the catalyst and the harsh reaction environment, effectively delaying and preventing catalyst deactivation. This is due to the microporous structure of the foam ceramic, which creates a confinement effect within the micropores. In this micro-confined space, CO2 molecules bind to the catalyst, and the microenvironment allows the metastable active centers to remain stable during the reaction, thereby enhancing the catalytic reaction. Simultaneously, the presence of the confined space significantly improves the catalytic activity and selectivity of the catalyst. Furthermore, the confined space greatly increases the contact time between CO2 molecules and the catalytic active centers, achieving a highly efficient catalytic reaction and improving CO2 conversion. In thermocatalytic reduction, this invention, through a confined reactor and the synergistic use of liquid metal GaIn, shortens the reaction time, increases the yield of carbon products, and improves the conversion rate of CO2. Subsequent low-temperature cooling is used to achieve rapid separation of carbon products and the catalyst. The confined reactor of this invention enables full mass and heat transfer of CO2 on the foam ceramic support inside the reactor. The horizontal and vertical arrangement of the support increases the residence time of CO2 in the foam ceramic channels, and the continuously alternating horizontal and vertical arrangement of the support exposes more active sites of the catalyst, thereby improving the catalytic efficiency of the entire reaction and achieving 100% CO2 conversion. It can also achieve 100% conversion of CO2 in the air.

[0018] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: (1) The confined reactor of the present invention can realize the full mass and heat transfer of CO2 on the foam ceramic support inside the reactor. The horizontal and vertically arranged support can increase the residence time of CO2 in the foam ceramic channels and enhance the catalytic reduction reaction. In addition, the horizontal and vertically alternating support can expose more active sites of the catalyst, thereby improving the catalytic efficiency of the entire reaction. When the reactor with the confined region is used for photocatalytic reduction and thermocatalytic reduction of CO2, the gas product yield is increased compared with the reactor without the confined reaction region. 2.5 times, the yield of solid carbon products increased by 3.74 times, and the CO2 conversion rate reached 100% during thermal catalytic reduction; (2) The gas, liquid and solid products generated by the catalytic reduction reaction in the confined reactor of the present invention under light-driven and heat-driven conditions can be continuously enriched inside the device, and the reaction efficiency of CO2 is not affected during the entire catalytic reduction reaction process. Furthermore, the catalytic reduction of the substrate and the enrichment of the product can be combined into one step to maximize the energy utilization rate. That is, during the CO2 catalytic solidification process inside the reaction chamber, carbon products will be enriched on the surface of the foam ceramic, thereby realizing the one-step operation of catalytic enrichment. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the confined reactor of the present invention;

[0020] Figure 2 This is a schematic diagram of the internal structure of the reaction chamber;

[0021] Figure 3 The SEM image of the catalyst used in Example 1;

[0022] Figure 4 The GC spectrum of the gaseous product obtained in Example 1;

[0023] Figure 5 The image shows the SEM image of the catalyst used in Example 2.

[0024] Figure 6 Here is an SEM image of the solid product obtained in Example 2;

[0025] Figure 7 The XRD pattern of the solid product obtained in Example 2;

[0026] Figure 8 Raman spectroscopy of the solid product obtained in Example 2;

[0027] Figure 9 This is the XPS image of the catalyst in Example 2 after 240 hours of continuous use. Detailed Implementation

[0028] like Figures 1-2 As shown, the microreactor for the conversion of carbon dioxide in air according to the present invention includes a reaction chamber 3, the shell of which is made of transparent glass. Multiple sets of catalyst carrier assemblies 31 are arranged inside the reaction chamber 3, with adjacent catalyst carrier assemblies 31 staggered along the material flow direction to form a baffle channel. Each set of catalyst carrier assemblies 31 consists of an integrally formed horizontally arranged catalyst carrier 311 and a vertically arranged catalyst carrier 312. The catalyst carrier is a foam ceramic catalyst carrier, on which a catalyst is loaded; the foam ceramic catalyst carrier is a porous foam ceramic catalyst carrier. Inside the reactor, the horizontally and vertically arranged catalyst carriers obstruct the vertical diffusion direction of carbon dioxide, increasing the residence time of carbon dioxide inside the reactor by continuously changing the diffusion direction, which is beneficial for the catalytic reaction and the maximization of energy exchange and utilization. Valves are installed on all pipes of the reactor of the present invention.

[0029] The transparent glass is an optically high-temperature resistant glass, with excellent light transmittance in the ultraviolet to infrared bands, and can withstand high temperatures of 1200℃ for extended periods. The inner diameter of reaction chamber 3 is 3cm, the height of reaction chamber 3 is 20cm, and the wall thickness of reaction chamber 3 is 0.3mm. The arrangement area of ​​multiple catalyst support components 31 occupies 6 / 7 to 8 / 9 of the volume of reaction chamber 3. The pore size on the foam ceramic catalyst support is 20 to 250 micrometers.

[0030] The catalyst is a photocatalyst In2O3 / TiO2; or the catalyst is a thermal catalyst liquid metal GaIn.

[0031] The inner wall of the reaction chamber 3 is provided with a slot for a foam ceramic catalyst carrier. The horizontally arranged catalyst carrier 311 is arc-shaped (except for the bottom catalyst carrier assembly 31, the horizontally arranged catalyst carrier 311 in the bottom catalyst carrier assembly 31 is circular and its diameter is consistent with the inner diameter of the reaction chamber). The horizontally arranged catalyst carrier 311 is embedded in the slot and fits and connects with the inner wall of the reaction chamber 3. The vertically arranged catalyst carrier 312 is rectangular. In each group of catalyst carrier assemblies 31, the vertically arranged catalyst carrier 312 and the horizontally arranged catalyst carrier 311 are integrally formed.

[0032] The reaction chamber is also equipped with a material inlet 14, a solid product outlet 15, a thermometer sensor socket 16, and a gas outlet 17. The material inlet 14 and the solid product outlet 15 are located at the bottom of the reaction chamber 3, while the thermometer sensor socket 16 and the gas outlet 17 are located at the top of the reaction chamber 3. The reactor also includes a light source 52, which is arranged around the outside of the reaction chamber 3, and the irradiation area of ​​the light source is the same length as the reaction chamber 3. The reactor also includes a secondary condenser I4, a secondary condenser II5, a reflux tank 6, and a reboiler 2. When the photocatalytic reduction of carbon dioxide is carried out, the secondary condenser I4 is used to condense and recover unreacted water vapor (condensation temperature is 85-95℃), and is connected to the reboiler 2 through a reflux peristaltic pump 7 to form an integrated circulation device; the secondary condenser II5 further condenses the mixed gas to completely separate the carbon dioxide and liquid products (condensation temperature is 60-80℃), and the condensed liquid products flow into the reflux tank 6. An external gas source is connected to the material inlet 14 at the bottom of the reaction chamber 3 via an inlet pipe. The outlet of the reboiler 2 is also connected to the material inlet 14 at the bottom of the reaction chamber. The gas outlet 17 at the top of the reaction chamber is connected to the condenser I4. The liquid outlet of the condenser I4 is connected to the inlet of the reboiler 2, and the gas outlet of the condenser I4 is connected to the inlet of the condenser II5. The liquid outlet of the condenser II5 is connected to the reflux tank 6, and the gas outlet of the condenser II5 is connected to the inlet pipe. A gas flow meter 1 is also installed on the inlet pipe. The reactor also includes an online gas chromatograph detection device 51, which is used to detect the composition of the gas in the condenser I4.

[0033] Example 1

[0034] Photocatalytic reduction of CO2 using the microreactor of this invention:

[0035] Photocatalyst loading on foam ceramic catalyst support: In2O3 / TiO2 photocatalyst was prepared into a suspension with a concentration of 5 mg / mL using water as solvent. The foam ceramic catalyst support was immersed in the catalyst suspension and dried in a vacuum drying oven. After drying, a foam ceramic support loaded with In2O3 / TiO2 catalyst was obtained, which was used for photocatalytic reduction of CO2. The pore size of the foam ceramic catalyst support was 20 micrometers.

[0036] A foam ceramic catalyst support loaded with a photocatalyst is assembled in reaction chamber 3. Under simulated sunlight source 52, carbon dioxide is catalytically reduced to gaseous and liquid products in a microfluidic confined reactor. This catalytic reduction process uses water vapor as the hydrogen source and simulated sunlight as the driving energy. Carbon dioxide mixes with water vapor inside reboiler 2 through gas flow meter 1. Under pressure, the mixed gas enters the reactor chamber. Carbon dioxide and water vapor molecules enter the micropores of the foam ceramic support and combine with the catalyst. Under the stimulation of the light source, photogenerated carriers generated by the catalyst carry out hydrogenation and deoxygenation reactions on CO2 molecules. The main gaseous product is… Methane and carbon monoxide, with methanol (in the gas phase at this stage) as the main liquid product, flow out of reaction chamber 3 along with the mixed gas stream and enter condenser I4. The gas phase after gas-liquid separation in condenser I4 enters condenser II5. Simultaneously, the gas phase after gas-liquid separation is analyzed for physical properties and purity by an online gas chromatograph 51. The liquid phase after gas-liquid separation in condenser I4 (water) enters reboiler 2. The liquid product after gas-liquid separation in condenser II5 enters reflux tank 6 for enrichment. The liquid product is analyzed for composition by nuclear magnetic resonance spectroscopy. The gas after gas-liquid separation in condenser II5 undergoes a new catalytic cycle. In this embodiment, the CO2 flow rate is 10 sccm, the main gaseous products are C2H6, CO, and CH4, and the main liquid product is methanol. The yield of the C2H6 gaseous product is 5.63 μmol·g. -1 h -1 The yield of the liquid product methanol was 20.56 μmol·g. -1 h -1 .

[0037] The photocatalyst used in Example 1 was analyzed by scanning electron microscopy, and the results are as follows: Figure 3 As shown, Figure 3 This indicates that the In2O3 / TiO2 was successfully synthesized and exhibits a plate-like structure. Figure 4 The spectrum of the gaseous product obtained in Example 1 is shown below. Figure 4It can be seen that the gaseous products contain multiple carbon products such as methane, carbon monoxide and ethane, indicating that the microfluidic confined reactor of the present invention is suitable for light-driven CO2 catalytic reduction and can enrich and separate the products.

[0038] Example 2

[0039] Thermocatalytic reduction of CO2 using a microreactor supported on GaIn according to the present invention:

[0040] Loading of thermal catalyst on foam ceramic catalyst support: Liquid metal (GaIn) was fluidized at 50°C and loaded onto a foam ceramic support at room temperature using an injection pump at a flow rate of 200 μL / min. The total loading amount was 10,000 μL and the loading time was 50 min. Due to the small porosity of the foam ceramic and the high surface tension of the liquid metal, the foam ceramic support supported the liquid metal. The pore size on the foam ceramic catalyst support was 250 micrometers.

[0041] A foam ceramic catalyst carrier loaded with a thermal catalyst is assembled in the reaction chamber. The reactor is placed in an environment of 250°C (the higher the temperature, the faster the reaction efficiency). The steam flow pipe is closed. Under thermal drive, carbon dioxide is catalytically reduced to solid carbon in the reactor. Carbon dioxide enters the reactor chamber and moves from the bottom to the top through diffusion under thermal stimulation. The horizontally arranged catalyst carrier 311 and the vertically arranged catalyst carrier 312 block the vertical diffusion direction of carbon dioxide. By continuously changing the diffusion direction of carbon dioxide, the residence time of carbon dioxide in the reactor chamber is increased. The external heat source is maintained within the range of 250°C. CO2 is completely converted in the reaction chamber, achieving a conversion rate of 100%. No gaseous or liquid products are produced in this catalytic process. The condenser I4, condenser II5, and reboiler 2 are in a non-operating state. An online gas chromatograph 51 is connected to valve I18 to analyze the gas. No CO2 flows out, indicating that the CO2 conversion rate in this embodiment reaches 100%. The catalyst on the catalyst carrier exhibits extremely high selectivity for the catalytic reduction of carbon dioxide to solid carbon matrix. In this embodiment, the CO2 flow rate is 0.3 sccm, the reaction time is 30 min, and the product is mainly solid carbon powder.

[0042] Under the same operating conditions (reactor placed at 250℃, CO2 flow rate of 0.3 sccm, reaction time of 30 min), the yield and CO2 conversion rate of CO2 catalytic conversion in different reactors were as follows: In a batch reactor (no catalyst support in the reaction chamber, liquid metal GaIn loading of 10000 μL), the CO2 to carbon yield was 215 μmol / h, and the CO2 conversion rate was 26.7%. In a reactor with only a horizontal catalyst support, the carbon product yield was 500 μmol / h, and the CO2 conversion rate was 62.2%. In the reactor of this invention containing both horizontal and vertical catalyst supports, the carbon product yield was 803 μmol / h, and the CO2 conversion rate reached 100%. This indicates that the present invention, by setting up a confined space within the reactor with horizontal and vertical catalyst supports, synergistically using liquid metal GaIn as a catalyst, greatly improves the CO2 to carbon product yield, achieving a CO2 conversion rate of 100%.

[0043] The thermal catalyst used in Example 2 was analyzed by scanning electron microscopy, and the results are as follows: Figure 5 As shown, Figure 5 This indicates that the GaIn catalyst was successfully loaded into the ceramic. Figure 6 The spectrum of the gaseous product obtained in Example 1 is shown below. Figure 7 It can be seen that carbon products are present in the solid products. Figure 8 XRD of solid carbon products Figure 9 Raman spectra of the solid carbon products were obtained. Different characterization methods confirmed the generation of solid carbon products within the confined reactor. Catalyst durability tests were conducted, and XPS results showed that the catalyst's intrinsic nature remained largely unchanged during ten consecutive days of operation. This demonstrates that the microfluidic confined reactor of this invention is suitable for thermally driven CO2 catalytic reduction and can effectively collect solid products.

[0044] Example 3

[0045] Thermocatalytic reduction of carbon dioxide in air using a microreactor loaded with GaIn according to the present invention:

[0046] Loading of thermal catalyst on foam ceramic catalyst support: Liquid metal (GaIn) was fluidized at 50°C and loaded onto a foam ceramic support at room temperature using an injection pump at a flow rate of 200 μL / min. The total loading amount was 20,000 μL and the loading time was 100 min. Due to the small porosity of the foam ceramic and the high surface tension of the liquid metal, the foam ceramic support supports the liquid metal. The pore size on the foam ceramic catalyst support is 400 micrometers.

[0047] A foamed ceramic catalyst support loaded with a thermal catalyst is assembled inside a reaction chamber. The reactor is placed in an environment of 300°C, and the steam flow pipe is closed. Under thermal drive, carbon dioxide is catalytically reduced to solid carbon in the reactor. Carbon dioxide enters the reactor chamber and, under thermal stimulation, moves continuously from the bottom to the top through diffusion. The horizontally arranged catalyst support 311 and the vertically arranged catalyst support 312 block the vertical diffusion direction of carbon dioxide. By continuously changing the diffusion direction of carbon dioxide, the residence time of carbon dioxide inside the reactor chamber is increased. The external heat source is maintained within the range of 300°C. This catalytic process does not involve the production of gaseous or liquid products. The sub-condensers I4, II5, and reboiler 2 are inactive. Unreacted gas enters the inlet pipe directly through the top gas outlet 17. An online gas chromatograph 51 connected to valve I18 performs quantitative analysis of the gas. All CO2 in the air is converted within the reaction chamber. The catalyst on the catalyst support exhibits extremely high selectivity for the catalytic reduction of CO2 in the air to a solid carbon matrix. In this embodiment, the air flow rate is 100 sccm, the reaction time is 1 hour, and the main product is solid carbon powder with a yield of 13.65 μmol / h.

[0048] Comparative Example 1

[0049] Thermocatalytic reduction of CO2 using a microfluidic confined reactor loaded with BiSn according to the present invention:

[0050] Loading of thermal catalyst on foam ceramic catalyst support: Liquid metal (BiSn) was fluidized at 140℃ and loaded onto a foam ceramic support at room temperature using an injection pump at a flow rate of 200 μL / min. The total loading amount was 10000 μL and the loading time was 50 min. The pore size on the foam ceramic catalyst support was 250 micrometers.

[0051] A foamed ceramic catalyst support loaded with a thermal catalyst is assembled inside a reaction chamber. The reactor is placed at 350°C, and the steam flow pipe is closed. Under thermal drive, carbon dioxide is catalytically reduced to solid carbon in the reactor. Carbon dioxide enters the reactor chamber and, under thermal stimulation, diffuses from the bottom to the top. The horizontally arranged catalyst support 311 and the vertically arranged catalyst support 312 block the vertical diffusion of carbon dioxide. By continuously changing the diffusion direction of carbon dioxide, the residence time of carbon dioxide inside the reactor chamber is increased. The external heat source is maintained within the 350°C range. The conversion takes place inside the reaction chamber. Unreacted carbon dioxide enters the inlet pipe directly through the top gas outlet 17 and undergoes a new round of catalytic reaction. This catalytic process does not involve the production of gaseous or liquid products. The sub-condensers I4, II5, and reboiler 2 are in a non-operating state. An online gas chromatograph 51 is connected to valve I18 to analyze the gas, and the CO2 conversion rate is found to be 70%. In this comparative example, the CO2 flow rate is 0.3 sccm, the reaction time is 30 min, the product is solid carbon powder, the carbon product yield is 563 μmol / h, and the CO2 conversion rate is 70%.

[0052] The results of CO2 catalytic reduction in Example 2, Comparative Example 1, and batch reactor are shown in Table 1.

[0053] Table 1

[0054] parameter Example 2 Comparative Example 1 batch reactor Reaction temperature (°C) 250 350 250 Reaction time (min) 30 30 30 Carbon yield (μmol / h) 803 563 215 <![CDATA[CO2 conversion rate (%)]]> 100 70.0 26.7 .

Claims

1. A microreactor for the conversion of carbon dioxide in air, characterized in that: The reaction chamber (3) is made of transparent glass. Multiple catalyst carrier assemblies (31) are arranged inside the reaction chamber (3). Adjacent catalyst carrier assemblies (31) are arranged alternately along the material flow direction to form a baffle channel. Each catalyst carrier assembly (31) consists of a horizontally arranged catalyst carrier (311) and a vertically arranged catalyst carrier (312) integrally formed. The catalyst carrier is a foam ceramic catalyst carrier, and a catalyst is loaded on the catalyst carrier. The foam ceramic catalyst carrier is a porous foam ceramic catalyst carrier. The reactor also includes a condenser I (4), a condenser II (5), a reflux tank (6), and a reboiler (2). An external gas source is connected to the material inlet (14) at the bottom of the reaction chamber (3) through an air inlet pipe. The outlet of the reboiler (2) is also connected to the material inlet (14) at the bottom of the reaction chamber. The gas outlet (17) at the top of the reaction chamber is connected to the condenser I (4). The liquid outlet of the condenser I (4) is connected to the inlet of the reboiler (2). The gas outlet of the condenser I (4) is connected to the inlet of the condenser II (5). The liquid outlet of the condenser II (5) is connected to the reflux tank (6). The gas outlet of the condenser II (5) is connected to the air inlet pipe.

2. The microreactor for converting carbon dioxide in air according to claim 1, characterized in that: The catalyst is a photocatalyst In2O3 / TiO2; or the catalyst is a thermal catalyst liquid metal GaIn.

3. The microreactor for converting carbon dioxide in air according to claim 2, characterized in that: Liquid metal GaIn was loaded onto a foam ceramic catalyst support: Liquid metal GaIn was fluidized at 50 °C and loaded onto a foam ceramic support at room temperature using an injection pump at a flow rate of 200 μL / min. The amount of GaIn loaded on the support was 10,000 μL. The pore size of the foam ceramic catalyst support was 250 μm.

4. The microreactor for converting carbon dioxide in air according to claim 1, characterized in that: The pore size of the foam ceramic catalyst support is 20-250 micrometers.

5. The microreactor for converting carbon dioxide in air according to claim 1, characterized in that: The inner wall of the reaction chamber (3) is provided with a slot for a foam ceramic catalyst carrier. The horizontally arranged catalyst carrier (311) is arc-shaped and is embedded in the slot to fit and connect with the inner wall of the reaction chamber (3). The vertically arranged catalyst carrier (312) is rectangular. In each catalyst carrier assembly (31), the vertically arranged catalyst carrier (312) and the horizontally arranged catalyst carrier (311) are integrally formed.

6. The microreactor for converting carbon dioxide in air according to claim 1, characterized in that: The reaction chamber is also provided with a material inlet (14), a solid product outlet (15), a thermometer sensor socket (16), and a gas outlet (17). The material inlet (14) and the solid product outlet (15) are located at the bottom of the reaction chamber (3), and the thermometer sensor socket (16) and the gas outlet (17) are located at the top of the reaction chamber (3).

7. The microreactor for converting carbon dioxide in air according to claim 1, characterized in that: The reactor also includes a light source (52), which is arranged around the outside of the reaction chamber (3), and the irradiation area of ​​the light source is the same length as the reaction chamber (3).

8. The microreactor for converting carbon dioxide in air according to claim 1, characterized in that: The air intake pipe is also equipped with a gas flow meter (1).

9. The microreactor for converting carbon dioxide in air according to claim 1, characterized in that: The reactor also includes an online gas chromatography detection device (51) for detecting the composition of the gas in the condenser I (4).

Images