Solar photo-thermal catalysis CO2 reduction integrated reactor

Abstract

The invention discloses a solar photo-thermal catalysis CO2 reduction integrated reactor which comprises a photo-thermal reactor, a gas source and a cold trap, the photo-thermal reactor comprises a reactor cavity, a light-transmitting upper cover is arranged at the top of the reactor cavity, a porous medium catalyst carrier and a heat insulation layer are arranged in the cavity, vertical through holes are uniformly distributed in the heat insulation layer, and capillary cores are filled in the vertical through holes; the lower part of the cavity is provided with a reactor gas inlet connected with a gas source, and the upper part of the cavity is provided with a reactor gas outlet connected with the cold trap; and a temperature monitoring device, an optical power meter, a pressure monitoring device and a gas chromatograph are also arranged. According to the invention, an energy-mass flow matched gas-liquid-solid three-phase reaction interface is constructed, the problems of low spectrum utilization rate, unbalanced reactant supply, large energy loss and the like of a traditional photocatalytic system are solved, sufficient energy and reactant molecules are continuously provided for the reaction, and the photocatalytic efficiency is improved. The reactor synergistically promotes the catalytic reaction from the aspects of energy conversion and mass transfer.

Description

Technical Field

[0001] This invention relates to a photothermal catalytic reactor, and more particularly to a solar photothermal catalytic CO2 reduction integrated reactor. Background Technology

[0002] The excessive consumption of traditional fossil fuels leads to massive carbon dioxide emissions, causing global problems such as the greenhouse effect and energy crisis. Developing new energy technologies, significantly reducing carbon dioxide emissions, and achieving sustainable development are imperative. Solar energy, as an inexhaustible renewable energy source, has broad prospects and enormous potential in the field of new energy utilization. Photocatalytic CO2 reduction to hydrocarbon fuels driven by solar energy has advantages such as a simple system and mild conditions, making it a very promising method to simultaneously alleviate energy shortages and environmental pollution problems.

[0003] The photocatalytic reduction of CO2 to produce hydrocarbon fuels is expressed as: CO2 + H2O = C x H y O z +O2. Photocatalytic CO2 reduction is a coupled process across multiple spatiotemporal scales involving solar energy capture, energy and mass transfer, and chemical transformation. Therefore, the reaction rate is not only affected by the performance of the catalyst itself, but also closely related to the distribution of multiple physical fields such as light transmission, temperature changes, and substance concentration during the reaction process. Unlike photocatalytic hydrogen production, the diffusion and adsorption of CO2 and the supply balance of reactants involved in photocatalytic CO2 reduction are also key limiting factors for its low reaction rate and energy efficiency. The reactor, as the carrier and site of the distribution of multiple physical fields in the above-mentioned stages, is very important. Current research focuses on experimental testing to improve the properties of the catalyst itself, while research on the regulation of catalytic performance by external reaction environment and parameters is still insufficient.

[0004] Furthermore, existing photocatalytic reactors are mostly limited to basic catalyst activity testing, neglecting the optimization of energy and mass transfer processes during the design process. Moreover, key functional modules such as real-time control of the reaction process and in-situ monitoring of parameters are not perfect, making it difficult to construct suitable CO2 reduction reaction conditions and unable to provide data support for the analysis of reaction mechanisms. Summary of the Invention

[0005] Purpose of the invention: The purpose of this invention is to provide an integrated solar photothermal catalytic CO2 reduction reactor that can promote CO2 adsorption, product desorption, regulate reactant supply, and increase reaction temperature, thereby driving the catalytic reaction and enabling in-situ real-time monitoring and analysis of reaction parameters.

[0006] Technical Solution: The solar photothermal catalytic CO2 reduction integrated reactor of the present invention includes a photothermal reactor, a gas source, and a cold trap. The photothermal reactor includes a reactor cavity with a light-transmitting cover at the top. A porous media catalyst carrier for loading the catalyst is provided inside the reactor cavity. The lower part of the reactor cavity has a reactor inlet connected to the gas source, and the upper part has a reactor outlet connected to the cold trap. A heat insulation layer for supporting and insulating the porous media catalyst carrier is provided below the porous media catalyst carrier. The heat insulation layer has evenly distributed vertical through holes, and the vertical through holes are filled with capillary cores for efficient transfer of the reaction solution from the lower part of the reactor cavity to the porous media catalyst carrier through capillary action. The reactor also includes a temperature monitoring device and a pressure monitoring device for monitoring the temperature and pressure of the photothermal reactor, respectively; a gas chromatograph connected to the outlet of the cold trap for detecting and quantitatively analyzing gaseous products; and a power meter for detecting the intensity of light irradiating the photothermal reactor.

[0007] The porous media catalyst support has the characteristics of high porosity and stable mechanical and chemical properties. It is used to load catalysts and construct a gas-liquid-solid three-phase reaction interface to continuously supply sufficient energy and reactant molecules for CO2 reduction reaction.

[0008] The heat insulation layer confines heat within the catalyst layer, increasing the catalytic reaction temperature. The uniformly distributed micro-vertical perforations on the heat insulation layer allow CO2 gas to be transported to the porous catalyst support, ensuring sufficient contact and interaction with the catalyst. The supply rate of the reaction solution can be adjusted by changing parameters such as the number and size of the capillary cores filling the vertical perforations of the heat insulation layer.

[0009] The photothermal reactor has a reactor inlet at the bottom of the cavity and a reactor outlet at the top of the cavity. The purpose is to allow CO2 gas to pass evenly from bottom to top through the porous medium catalyst carrier in the middle of the cavity, thereby promoting CO2 adsorption and product desorption.

[0010] The light-transmitting cover is a quartz glass cover plate, which has anti-fog and high light transmittance properties, and is used to prevent the scattering of incident light caused by the condensation of water vapor into droplets.

[0011] The photothermal reactor can be used for CO2 reduction experiments under different reaction conditions. The porous medium catalyst support, heat insulation layer, and capillary core are detachable. After disassembly, the catalyst can be dispersed in the reaction solution to achieve CO2 reduction testing under liquid-solid suspension conditions. Alternatively, after disassembling the heat insulation layer and capillary core, the catalyst can be loaded onto the porous medium catalyst support, and wetted CO2 containing water vapor can be introduced to achieve CO2 reduction testing under gas-solid phase conditions.

[0012] The cold trap includes a foam insulation box, a gas collection bottle, and a thermoelectric cooling element. The gas inlet of the gas collection bottle is connected to the reactor, and the gas outlet is connected to a gas chromatograph. The cold end of the thermoelectric cooling element is placed on the top of the foam insulation box, and the hot end is placed on the outside, forming a low-temperature zone inside the foam insulation box. The gas flows out from the gas outlet of the reactor and enters the gas collection bottle for cooling and drying of the reaction gas, thereby collecting organic matter and liquid products.

[0013] The gas source and the photothermal reactor are connected in sequence by a gas flow meter and a mixing tank; the mixing tank is connected to the gas inlet of the photothermal reactor through a gas pipeline to achieve uniform mixing of different gases in the mixing tank.

[0014] The temperature monitoring device includes a thermocouple, which is inserted into the catalyst layer through a temperature monitoring interface on the reactor. The thermocouple is connected to a data acquisition device for recording temperature data.

[0015] The pressure monitoring device is a differential pressure transmitter, which displays pressure changes in real time by a digital controller.

[0016] A sealing rubber ring is provided between the light-transmitting top cover and the reactor cavity.

[0017] Beneficial effects: Compared with the prior art, the present invention achieves the following significant effects:

[0018] (1) The photothermal reactor of the present invention has a porous medium catalyst support in the middle for loading the catalyst. The lower end has a heat insulation layer to isolate heat transfer and increase the catalyst temperature. There are through holes on the heat insulation layer, and the reaction gas passes through the catalyst uniformly from bottom to top, promoting the adsorption of reactants and the desorption of products. The through holes are filled with capillary wicks. The through holes and capillary wicks are used for the efficient transport of reaction gas and reaction solution and are enriched on the porous medium catalyst support, thereby constructing a gas-liquid-solid three-phase reaction interface with energy-mass flow matching. This solves the problems of low spectral utilization, unbalanced supply of reactants and large energy loss in traditional photocatalytic systems, and provides sufficient energy and reactant molecules for the reaction. The reactor promotes the catalytic reaction in a synergistic way in terms of energy conversion and mass transfer.

[0019] (2) Existing photocatalytic reaction systems usually require external connection to a cooling circulating water machine, which is complex in structure. The cold trap of the present invention uses thermoelectric cooling chip to achieve organic matter condensation to prevent it from entering the chromatogram and damaging the chromatographic column, or to collect liquid phase products. It has the characteristics of simple structure, flexible assembly and convenient operation.

[0020] (3) The photothermal reactor of the present invention can be used for CO2 reduction experiments under different reaction conditions. The porous medium catalyst support, heat insulation layer and capillary core are detachable. After disassembly, the catalyst can be dispersed in the reaction solution to realize CO2 reduction test under liquid-solid suspension system conditions; or, after disassembling the heat insulation layer and capillary core, the catalyst can be loaded on the porous medium catalyst support and wetted CO2 containing water vapor can be introduced to realize CO2 reduction test under gas-solid system conditions; therefore, the solar photothermal catalytic CO2 reduction integrated reactor of the present invention can be used for reaction test under liquid-solid suspension system and gas-solid system conditions.

[0021] (4) In addition to quantitative analysis of photocatalytic CO2 reduction products, this invention can also monitor light intensity, temperature and pressure, providing data support for the analysis of reaction mechanism. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall composition of this integrated reactor;

[0023] Figure 2 This is a schematic diagram of the photothermal reactor structure of this integrated reactor;

[0024] Figure 3 This is a schematic diagram of the cold trap structure of the integrated reactor;

[0025] Figure 4 The graph shows the results of CO2 reduction reaction tests in two application processes using the integrated reactor of the present invention. Detailed Implementation

[0026] The present invention will now be described in further detail.

[0027] See Figures 1 to 3 An integrated solar photothermal catalytic CO2 reduction reactor includes a photothermal reactor 1, a gas source, a gas flow meter 2, a gas mixing tank 3, a cold trap 4, a gas chromatograph 5, a power meter 6, a data acquisition device 7, a temperature monitoring device, and a pressure monitoring device 9.

[0028] The photothermal reactor 1 includes a reactor cavity 18, with a light-transmitting cover 10 at the top. The reactor cavity 18 contains a porous medium catalyst support 12 for loading a catalyst to form a gas-liquid-solid three-phase reaction interface. The lower part of the reactor cavity 18 has a reactor inlet 14 connected to a gas source, and the upper part has a reactor outlet 16 connected to a cold trap 4. CO2 gas passes through the porous medium catalyst support 12 in the reactor cavity 18 from bottom to top, promoting CO2 adsorption and product desorption.

[0029] A heat insulation layer 17 is provided inside the reactor cavity 18 below the porous media catalyst support 12 to insulate and concentrate heat in the catalyst layer, thereby increasing the catalytic reaction temperature. The heat insulation layer 17 has uniformly distributed micro-vertical through-holes, allowing CO2 gas to be transported to the porous media catalyst support 12 for full contact and interaction with the catalyst. The vertical through-holes of the heat insulation layer 17 are filled with capillary wicks 13, enabling efficient transport of the reaction solution from the lower part of the reactor cavity 18 to the porous media catalyst support 12 through capillary action. The supply rate of the reaction solution can be adjusted by changing parameters such as the number and size of the capillary wicks 13.

[0030] The photothermal reactor 1 is equipped with a temperature monitoring device and a pressure monitoring device 9 for testing the pressure inside the reactor. The temperature monitoring device includes a thermocouple 8, which is inserted into the catalyst layer through a temperature monitoring interface 11 on the photothermal reactor 1. The thermocouple 8 is connected to a data acquisition device 7 for recording temperature data. The pressure monitoring device is a differential pressure transmitter, and the pressure changes are displayed in real time by a digital controller.

[0031] This embodiment also includes an optical power meter 6 for detecting the light intensity irradiated on the photothermal reactor 1; and a gas chromatograph 5 for detecting and quantitatively analyzing gaseous products is connected to the outlet of the cold trap 4.

[0032] If the gas source includes two or more gases, a gas flow meter 2 and a mixing tank 3 are connected sequentially between the gas source and the photothermal reactor 1. In this embodiment, the gas source consists of a high-purity CO2 cylinder and a high-purity Ar cylinder. When the gas source is only high-purity CO2, the gas flow meter 2 is connected to the high-purity CO2 cylinder, allowing the CO2 flow rate to be adjusted from 0 mL / min to 100 mL / min. The other end of the flow meter is connected to the lower inlet of the reactor via a gas pipeline, allowing the CO2 to enter the reactor. When the gas source also includes high-purity Ar, the gas flow meter 2 is connected in parallel to another high-purity Ar cylinder. By adjusting the relative flow rates of CO2 and Ar, CO2 and Ar are uniformly mixed in the mixing tank 3, achieving CO2 concentration control from 0% to 100%.

[0033] like Figure 2In this embodiment, the photothermal reactor 1 is a photocatalytic CO2 reduction reaction generating device. The main body of the photothermal reactor 1 is a flat plate structure with a side length of 200 mm and a height of 50 mm. It includes a light-transmitting top cover 10, a sealing rubber ring 15, a reactor cavity 18, a reactor inlet 14, a reactor outlet 16, a temperature monitoring interface 11, a porous media catalyst carrier 12, a heat insulation layer 17, and a capillary wick 13. The reactor inlet 14 is connected to the mixing tank 3 through a gas pipeline, and the reactor outlet 16 is connected to the cold trap 4 through a gas pipeline. The reactor inlet 14, the reactor outlet 16, and the temperature monitoring interface 11 all have a diameter of 5 mm and are sealed with rubber plugs and threaded caps. The reactor inlet 14 and the reactor outlet 16 are respectively connected to the gas pipeline to achieve sealing and flexible and quick assembly and disassembly. The porous media catalyst carrier 12 located in the middle of the reactor cavity 18 uses a polyacrylonitrile fiber membrane with a side length of 200 mm and a thickness of 0.3 mm to support the catalyst. The reactor cavity 18 is equipped with 20 A PTFE insulation layer 17, 1 mm thick, is placed at the lower end of the porous catalyst carrier 12. This layer supports the porous catalyst carrier 12 and isolates it from heat transfer, thus increasing the catalytic reaction temperature. The PTFE insulation layer 17 has uniformly distributed 3 mm diameter through-holes to facilitate the flow and transport of reaction gases. The through-holes are filled with 1 mm diameter dust-free paper capillary wicks 13, enabling efficient transport of the reaction solution from the lower part of the reactor chamber 18 to the quartz membrane. The porous catalyst carrier 12, PTFE insulation layer 17, and capillary wicks 13 are all detachable, allowing for CO2 reduction tests under both liquid-solid and gas-solid phase conditions. In this embodiment, the light-transmitting top cover 10 is a quartz glass cover with anti-fogging and high light transmittance properties, preventing incident light scattering caused by water vapor condensation and droplet formation. A sealing rubber ring 15 is provided between the light-transmitting top cover 10 and the reactor chamber 1.

[0034] like Figure 3 In this embodiment, the cold trap 4 includes a foam insulation box 21, a gas collection bottle 20, and a thermoelectric cooler 19. The gas inlet of the gas collection bottle 20 is connected to the reactor, and the gas outlet is connected to the gas chromatograph 5. The cold end of the thermoelectric cooler 19 is placed on top of the foam insulation box 21, and the hot end is placed on the outside, forming a low-temperature zone inside the foam insulation box 21. Gas flows out from the reactor outlet 16 and enters the gas collection bottle 20 for cooling and drying of the reaction gas, thereby collecting organic matter and liquid products. In this embodiment, the gas collection bottle 20 is a quartz bottle.

[0035] The following are two specific application processes using the solar photothermal catalytic CO2 reduction integrated reactor described above:

[0036] Application 1:

[0037] 200 mg of ZnIn2S4 nanoparticle catalyst and 1 g of polyacrylonitrile powder were dispersed in 10 mL of N,N dimethylformamide solution and stirred at 343 K for 6 h until homogeneous. Then, a porous catalyst membrane was prepared by electrospinning.

[0038] A pre-cut dust-free paper capillary core 13 is inserted into the through-hole of the polytetrafluoroethylene insulation layer 17, and then placed into the photothermal reactor 1. 20 mL of reaction solution is added into the photothermal reactor 1, and the bottom end of the capillary core 13 is inserted into the reaction solution. The reaction solution is then transported to the porous catalyst membrane through capillary action.

[0039] The reactor chamber 18 was sealed to the quartz cover plate with a U-clamp. The reactor inlet 14 was then connected to the mixing tank 3, and the reactor outlet 15 was connected to the quartz bottle inside the cold trap 4. A 300 W xenon lamp was placed on top of the photothermal reactor 1. The CO2 flow rate was set to 100 sccm. After purging the reactor for 30 minutes, the CO2 flow rate was set to 1.5 sccm, and the xenon lamp was turned on to begin the three-phase interface CO2 reduction reaction test. The main product was CO, and the yield was as follows: Figure 4 The three phases are shown in the diagram.

[0040] Application 2:

[0041] 20 mg of ZnIn2S4 nanoparticle catalyst particles were dispersed in 20 mL of reaction solution and sonicated at room temperature for 30 min until homogeneous. The catalyst slurry was then directly poured into photothermal reactor 1.

[0042] The reactor chamber 18 is sealed to the quartz cover plate with a U-clamp. The reactor inlet 14 is then connected to the mixing tank 3, and the reactor outlet 16 is connected to the quartz bottle inside the cold trap 4. A 300 W xenon lamp is placed on top of the photothermal reactor 1. The CO2 flow rate is set to 100 sccm. After purging the air from the photothermal reactor 1 for 30 minutes, the CO2 flow rate is set to 1.5 sccm. The xenon lamp is then turned on to begin the liquid-solid phase CO2 reduction reaction test. The main product is CO, and the yield is as follows: Figure 4 The liquid-solid phase is shown.

Claims

1. A solar-thermal catalytic CO2 reduction integrated reactor, characterized in that, The system includes a photothermal reactor (1), a gas source, and a cold trap (4). The photothermal reactor (1) includes a reactor cavity (18), with a light-transmitting cover (10) at the top. A porous media catalyst support (12) for loading the catalyst is provided inside the reactor cavity (18). The lower part of the reactor cavity is provided with a reactor inlet (14) connected to the gas source, and the upper part is provided with a reactor outlet (16) connected to the cold trap (4). Below the porous media catalyst support (12) is a structure for supporting the porous media catalyst support (12) and providing thermal insulation. The heat insulation layer (17) is evenly distributed with vertical through holes, and the vertical through holes are filled with capillary cores (13) for efficient transfer of the reaction solution from the lower part of the reactor cavity (18) to the porous medium catalyst support (12) through capillary action; it also includes a temperature monitoring device and a pressure monitoring device (9) for monitoring the temperature and pressure inside the photothermal reactor; a gas chromatograph (5) connected to the outlet of the cold trap (4) for detecting and quantitatively analyzing gaseous products; and a light power meter (6) for detecting the intensity of light irradiating the photothermal reactor (1).

2. The integrated solar photothermal catalytic CO2 reduction reactor according to claim 1, characterized in that, The cold trap (4) includes an insulated box (21), a gas collection bottle (20), and a thermoelectric cooler (19); the gas inlet of the gas collection bottle (20) is connected to the photothermal reactor (1), and the gas outlet is connected to the gas chromatograph (5); the cold end of the thermoelectric cooler (19) is placed on the top of the insulated box (21), and the hot end is placed on the outside, for forming a low temperature zone inside the insulated box (21); the gas flows out from the reactor outlet (16) and enters the gas collection bottle (20) for cooling and drying of the reaction gas, and for collecting organic matter and liquid products.

3. The integrated solar photothermal catalytic CO2 reduction reactor according to claim 1, characterized in that, The porous medium catalyst support (12), heat insulation layer (17), and capillary core (13) are all detachable. After disassembly, the catalyst can be dispersed in the reaction solution, which can realize CO2 reduction test under liquid-solid phase suspension system conditions.

4. The integrated solar photothermal catalytic CO2 reduction reactor according to claim 1, characterized in that, A mixing tank (3) is connected between the gas source and the photothermal reactor (1); the mixing tank (3) is connected to the reactor inlet (14) through a gas pipeline to achieve uniform mixing of different gases in the mixing tank (3).

5. The integrated solar photothermal catalytic CO2 reduction reactor according to claim 1, characterized in that, A gas flow meter (2) for controlling the gas flow rate is connected between the gas source and the photothermal reactor (1).

6. The integrated solar photothermal catalytic CO2 reduction reactor according to claim 1, characterized in that, The temperature monitoring device includes a thermocouple (8), which is inserted into the catalyst layer through a temperature monitoring interface (11) on the photothermal reactor (1).

7. The integrated solar photothermal catalytic CO2 reduction reactor according to claim 6, characterized in that, The thermocouple (8) is connected to a data acquisition unit (7) for recording temperature data.

8. The integrated solar photothermal catalytic CO2 reduction reactor according to claim 1, characterized in that, The pressure monitoring device (9) is a differential pressure transmitter, and the pressure change is displayed in real time by a digital controller.

9. The integrated solar photothermal catalytic CO2 reduction reactor according to claim 1, characterized in that, The light-transmitting cover (10) is a quartz glass cover plate with anti-fog and high light transmittance characteristics, which is used to prevent the scattering of incident light caused by the condensation of water vapor into droplets.

10. The solar photothermal catalytic CO2 reduction integrated reactor according to claim 1, characterized in that, A sealing rubber ring (15) is provided between the light-transmitting top cover (10) and the reactor cavity (1).

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