A continuous flow photothermal catalytic reactor and its operation method

Abstract

This invention relates to the field of photothermal catalytic reaction and continuous flow chemical equipment technology, and discloses a continuous flow photothermal catalytic reactor and its operation method. The reactor includes an inlet mixing module, a heat recovery preheating module, a photothermal reaction module, a cooling and condensation module, an online analysis module, and a tail gas recirculation module. The photothermal reaction module is equipped with a transparent quartz window, a light source, a catalyst bed, a reflective sidewall, and a heat insulation layer. The light source illuminates the catalyst bed through the transparent quartz window, and the reflective sidewall reflects light that does not directly act on the catalyst bed back to the reaction area, thereby improving light utilization efficiency and promoting a spatially uniform distribution of the light and heat fields. The transparent quartz window can also be used to observe the light-receiving area of ​​the catalyst bed and the reaction state. After mixing and heat recovery preheating, the reaction gas enters the photothermal reaction module to undergo a continuous flow photothermal catalytic reaction. After cooling and condensation and online analysis, the unreacted gas can be recycled back to the inlet. This reactor has advantages such as low energy consumption, high photothermal utilization efficiency, high visualization, stable continuous operation, and wide applicability.

Description

Technical Field

[0001] This invention relates to the field of photothermal catalytic reaction and continuous flow chemical equipment technology, and in particular to a continuous flow photothermal catalytic reactor and its operation method, which can be applied to fields such as gas phase catalytic conversion, carbon resource utilization, environmental catalysis and photothermal chemical reactions. Background Technology

[0002] Photothermal catalysis technology drives chemical reactions through the synergistic effect of light and heat energy, and has broad application prospects in energy conversion, environmental governance, and gas resource utilization. Compared with traditional thermocatalysis, photothermal catalysis can utilize light to create a localized high-energy reaction environment on the catalyst surface, thereby reducing overall reaction energy consumption and improving reaction efficiency and controllability.

[0003] Currently, most common photothermal catalytic reactors employ simple external illumination structures, such as quartz tube external illumination or batch reaction systems. These devices typically suffer from the following problems:

[0004] 1) Low light energy utilization efficiency and uneven light distribution;

[0005] 2) The system lacks an effective heat recovery structure, resulting in high overall energy consumption.

[0006] 3) The single-use efficiency of reactant gases is limited, and unreacted gases are directly emitted;

[0007] 4) The stability of continuous flow operation is insufficient, making it difficult to meet the requirements for stable reaction over a long period of time;

[0008] 5) The integration between the reaction, cooling, analysis, and circulation modules is low, which is not conducive to engineering applications;

[0009] 6) The existing reactors have low visualization capabilities, making it difficult to directly observe the light-receiving area of ​​the catalyst bed and the reaction state, which is not conducive to teaching demonstrations and experimental process research.

[0010] Therefore, developing a photothermal catalytic reactor with a uniform photothermal field, high light utilization rate, continuous flow circulation operation, high visibility, and modular structure is of great significance for improving the efficiency of photothermal catalytic reactions and promoting the engineering of related technologies. Summary of the Invention

[0011] (a) Purpose of the invention

[0012] The purpose of this invention is to provide a continuous-flow photothermal catalytic reactor and its operation method to solve the problems of low photothermal utilization efficiency, high energy consumption, insufficient continuous operation capability, and low system visualization in existing photothermal catalytic devices. Simultaneously, this invention achieves a spatially uniform distribution of the light and heat fields within the catalytic bed region through the coordinated design of a transparent quartz window and reflective sidewalls, thereby improving light energy utilization efficiency and reducing system energy consumption. Furthermore, this invention allows for direct observation of the light-receiving area and reaction state of the catalytic bed through the transparent quartz window, making it suitable for teaching demonstrations, experimental observations, and research on photothermal catalytic processes.

[0013] (II) Technical Solution

[0014] To achieve the above objectives, the present invention adopts the following technical solution:

[0015] A continuous flow photothermal catalytic reactor includes an inlet mixing module, a heat recovery preheating module, a photothermal reaction module, a cooling and condensation module, an online analysis module, and an exhaust gas recirculation module.

[0016] 1. Intake Mixing Module

[0017] The air intake mixing module includes at least one reactant gas inlet, a mass flow controller, and a mixing chamber;

[0018] Each reactant gas is regulated by a mass flow controller before entering the mixing chamber, achieving proportional control and uniform mixing of the reactant gases.

[0019] 2. Heat recovery preheating module

[0020] The heat recovery preheating module includes a heat exchanger;

[0021] One side of the heat exchanger is connected to the high-temperature tail gas at the reactor outlet, and the other side is connected to the inlet reaction gas. The feed gas is preheated through heat exchange between the high-temperature tail gas and the inlet gas.

[0022] Preferably, the heat exchanger is a spiral coil heat exchange structure.

[0023] 3. Photothermal reaction module

[0024] The photothermal reaction module includes: 1) a reaction chamber; 2) a transparent quartz window; 3) a light source; 4) a catalyst bed; 5) a reflective sidewall; and 6) a heat insulation layer.

[0025] The transparent quartz window is located at the top of the reaction chamber to introduce external light and to observe the light-receiving area and state of the catalyst bed.

[0026] The light source is located above the transparent quartz window and is used to provide uniform illumination to the catalyst bed.

[0027] The catalytic bed is located inside the reaction chamber and within a uniformly illuminated area for continuous photothermal catalytic reaction.

[0028] The reflective sidewalls are located on both sides of the reaction chamber and are used to reflect light that does not directly irradiate the catalyst bed back to the reaction area, thereby improving light utilization efficiency and promoting uniform distribution of the light field within the catalyst bed area.

[0029] The heat insulation layer is disposed around the reaction chamber to reduce heat loss and improve the system's thermal efficiency.

[0030] Preferably, the reflective sidewall is one or more of an arc-shaped reflective structure, a parabolic reflective structure, or a high-reflectivity metal reflective structure.

[0031] Preferably, the light source is one or more of a xenon lamp, an LED array, a halogen lamp, or a solar simulation light source.

[0032] Preferably, the catalytic bed is a fixed bed, a porous bed, or a structured catalytic bed.

[0033] 4. Cooling and condensation module

[0034] The cooling and condensation module is located at the outlet of the photothermal reaction module and includes a cooling device and a condensation unit;

[0035] It is used to cool the high-temperature gas after the reaction and to collect the condensate.

[0036] Preferably, the cooling device adopts a cooling coil structure.

[0037] 5. Online Analysis Module

[0038] The online analysis module is connected to the cooling and condensation module and is used to detect the composition of the reaction products in real time.

[0039] Preferably, the online analysis module includes one or more of a gas chromatograph, a mass spectrometer, or an infrared gas analyzer.

[0040] 6. Exhaust Gas Recirculation Module

[0041] The exhaust gas recirculation module includes a recirculation pump and a return pipeline;

[0042] Unreacted gas is transported by a circulating pump and then re-enters the intake mixing module, thus achieving the recycling of reactant gas.

[0043] (III) Operating Method

[0044] An operation method based on the above-mentioned continuous flow photothermal catalytic reactor includes the following steps:

[0045] 1. The reactant gases are introduced separately into the mass flow controller and mixed uniformly in the mixing chamber;

[0046] 2. The mixed gas enters the heat recovery preheating module, where it is preheated by exchanging heat with the high-temperature exhaust gas;

[0047] 3. The preheated gas enters the photothermal reaction module, where a continuous photothermal catalytic reaction occurs under the illumination introduced by the transparent quartz window, the homogenization effect of the light field formed by the reflective sidewall, and the action of the catalytic bed.

[0048] 4. After the reaction, the gas enters the cooling and condensation module for cooling and condensation;

[0049] 5. The cooled gas enters the online analysis module for composition detection;

[0050] 6. Unreacted gases are returned to the intake mixing module via the exhaust gas recirculation module to continue participating in the reaction. Beneficial effects

[0051] Compared with the prior art, the present invention has the following advantages:

[0052] 1. High uniformity of photothermal field: Through the coordinated design of the uniform light source at the top and the reflective sidewall, the light field is uniformly distributed within the catalytic bed area, and the spatial consistency between the light field and the thermal field is promoted, thereby improving the stability of the catalytic reaction.

[0053] 2. High light utilization efficiency: The reflective sidewalls reflect and recover scattered light from the edges, increasing the effective illumination ratio and reducing light energy loss.

[0054] 3. Low energy consumption: Through photothermal synergy, heat recovery heat exchange structure and uniform photothermal field design, the external heating demand and overall system energy consumption are reduced.

[0055] 4. High degree of visualization: Through the transparent quartz window and open lighting structure, the light-receiving area of ​​the catalyst bed and the changes in the reaction state can be directly observed, which is suitable for teaching demonstrations, experimental observations and photothermal catalysis process research.

[0056] 5. Stable continuous flow operation: The continuous flow structure combined with the tail gas recirculation module can maintain a stable reaction environment, improve the ability of continuous reaction operation and the utilization rate of raw materials.

[0057] 6. High degree of modularity: Each functional module can be independently disassembled, replaced and expanded, making it suitable for different types of photothermal catalytic reaction systems. Attached Figure Description

[0058] Figure 1 This is a schematic diagram of the overall structure of the continuous flow photothermal catalytic reactor of the present invention;

[0059] Figure 2This is a schematic diagram of the reflective sidewall and light field homogenization structure of the present invention;

[0060] Figure 3 This is a schematic diagram of the exhaust gas recirculation module structure of the present invention. Detailed Implementation

[0061] The present invention will be further described below with reference to the embodiments, but the present invention is not limited to the following embodiments. Adjustments to the composition of the reaction gas, the form of the light source, the operating conditions, and the catalyst structure without departing from the principle of the present invention are all within the scope of protection of the present invention.

[0062] Example 1: Device Structural Parameters Example

[0063] This embodiment provides a continuous flow photothermal catalytic reactor. The reaction chamber adopts a flat structure with an effective volume of 20 mL, a catalyst bed area of ​​4 cm², and a catalyst bed thickness of 2 mm. A transparent quartz window with a thickness of 2 mm and a light-transmitting area of ​​6 cm² is provided at the top of the reaction chamber. A broadband xenon lamp is used as the light source, and the light power density can be adjusted within the range of 0.5–5 W cm⁻².

[0064] The reaction chamber is equipped with arc-shaped reflective sidewalls on both sides, made of high-reflectivity metal or metal-coated material, to reflect light that does not directly illuminate the catalytic bed back to the catalytic bed area. A heat insulation layer is installed around the reaction chamber to reduce heat loss. The inlet reaction gas is preheated by a spiral coil heat exchanger before entering the reaction chamber. The high-temperature gas after the reaction releases heat through the same heat exchange system, which is then used to preheat the inlet gas.

[0065] This structure can increase the effective light irradiation ratio in the catalyst bed region, promote the uniform spatial distribution of the light and heat fields, and allow direct observation of the light-receiving state of the catalyst bed and changes in the reaction region through a transparent quartz window. Example 2: Continuous flow photothermal catalytic dry reforming reaction of methane

[0066] This embodiment uses the continuous flow photothermal catalytic reactor of the present invention to carry out the dry reforming reaction of methane.

[0067] 1. Composition of the reaction apparatus

[0068] The reactor includes: 1) a methane gas source and a carbon dioxide gas source; 2) a mass flow controller; 3) a gas mixing chamber; 4) a heat recovery heat exchanger; 5) a photothermal reaction module; 6) a cooling and condensation module; 7) an online gas analysis module; and 8) a tail gas recirculation module.

[0069] The photothermal reaction module includes: 1) a transparent quartz window; 2) a broadband light source; 3) a fixed-bed catalytic bed; 4) a reflective sidewall; and 5) a heat insulation layer.

[0070] 2. Catalyst

[0071] The catalyst used is a Ni / CeO2 photothermal catalyst, which is packed in the fixed-bed catalytic region.

[0072] The Ni loading is 10 wt%.

[0073] The catalyst loading amount is 50 mg.

[0074] 3. Reaction conditions

[0075] The volume ratio of methane to carbon dioxide is 1:1.

[0076] The total gas flow rate is 50 mL / min.

[0077] The mixed gas before the reaction is preheated by a heat recovery heat exchanger before entering the photothermal reaction module.

[0078] The light source is a xenon lamp.

[0079] The light power density is 2 W / cm² 2 .

[0080] The reaction temperature was controlled at 500 ℃.

[0081] 4. Reaction process

[0082] After being preheated, the mixed gas enters the photothermal reaction zone, where a dry reforming reaction of methane occurs on the surface of the Ni / CeO2 catalyst under the synergistic effect of photothermal action.

[0083] CH4 + CO2 → 2CO + 2H2

[0084] After the reaction, the high-temperature gas releases heat through a heat recovery heat exchanger and then enters the cooling and condensation module, followed by the online gas chromatography analysis module.

[0085] Unreacted gases are returned to the mixing chamber via the exhaust gas recirculation module. 5. Implementation Results

[0086] In this embodiment, the reflective sidewall can reflect light from the edge area back to the catalytic bed area, thereby improving the effective light utilization rate.

[0087] The transparent quartz window allows direct observation of the catalytic bed's light exposure and changes in the reaction zone, making it suitable for teaching demonstrations and experimental observation.

[0088] The heat recovery structure can effectively reduce the overall energy consumption of the system.

[0089] The continuous flow structure and tail gas recirculation module improve reaction stability and feedstock utilization.

[0090] Example 3 Continuous-flow photothermal catalytic CO2 hydrogenation methanation reaction

[0091] This embodiment uses the continuous flow photothermal catalytic reactor of the present invention to carry out the CO2 hydrogenation methanation reaction.

[0092] 1) Composition of the reaction apparatus

[0093] The reactor structure is the same as in Example 1.

[0094] 2) Catalyst

[0095] The catalyst is the same as that used in Example 1.

[0096] 3) Reaction conditions

[0097] The volume ratio of carbon dioxide to hydrogen is 1:4.

[0098] The total gas flow rate is 60 mL / min.

[0099] The reaction gas is preheated by a heat recovery heat exchanger before entering the photothermal reaction module.

[0100] The light source is a broadband xenon lamp.

[0101] The light power density is 1.5 W / cm². 2 .

[0102] The reaction temperature was controlled at 350 ℃.

[0103] 4) Reaction process

[0104] The reaction gas enters the mixing chamber after being regulated by a mass flow controller, and is preheated by a heat recovery heat exchanger.

[0105] The preheated gas mixture enters the photothermal reaction module, where it undergoes a CO2 hydrogenation methanation reaction on the surface of the Ni / CeO2 catalyst under the synergistic effect of photothermal action.

[0106] CO2 + 4H2 → CH4 + 2H2O

[0107] After the reaction, the gas is cooled and the condensate is collected by a cooling and condensation module.

[0108] After the exhaust gas is detected by the online analysis module, the unreacted gas is re-entered into the reaction system through the exhaust gas recirculation module.

[0109] 5) Implementation Results

[0110] In this embodiment, the continuous flow photothermal catalytic reactor can maintain a stable reaction under low external heating conditions.

[0111] The Ni / CeO2 catalyst exhibits good CO2 activation ability and reaction stability under the synergistic effect of photothermal action.

[0112] The reflective sidewalls increase the effective light irradiation ratio within the catalytic bed region and promote a uniform distribution of the photothermal field.

[0113] Meanwhile, the heat recovery structure reduces the overall energy consumption of the system, and the exhaust gas recirculation structure improves the utilization rate of the reaction gas.

Claims

1. A continuous flow photothermal catalytic reactor, characterized in that, include: The system includes an intake mixing module, a heat recovery and preheating module, a photothermal reaction module, a cooling and condensation module, an online analysis module, and an exhaust gas recirculation module. The air intake mixing module includes a reaction gas inlet, a mass flow controller, and a mixing chamber, which are used to regulate and mix the flow rate of the reaction gas. The heat recovery preheating module includes a heat exchanger, which is used to preheat the inlet reaction gas using the high-temperature gas after the reaction. The photothermal reaction module includes a reaction chamber, a transparent quartz window, a light source, a catalyst bed, a reflective sidewall, and a heat insulation layer. The light source provides illumination to the catalyst bed through the transparent quartz window, and the reflective sidewall is used to reflect light that does not directly illuminate the catalyst bed back to the catalyst bed area. The cooling and condensation module is located at the outlet of the photothermal reaction module and is used to cool and condense the gas after the reaction. The online analysis module is connected to the cooling and condensation module and is used to detect the composition of the reaction products; The exhaust gas recirculation module includes a recirculation pump and a return pipeline, which is used to re-transport unreacted gas to the intake gas mixing module.

2. The continuous flow photothermal catalytic reactor according to claim 1, characterized in that: The transparent quartz window is located at the top of the reaction chamber to enable external light transmission and to observe the light-receiving area and state of the catalyst bed.

3. The continuous flow photothermal catalytic reactor according to claim 1, characterized in that: The reflective sidewall is one or more of an arc-shaped reflective structure, a parabolic reflective structure, or a high-reflectivity metal reflective structure, used to improve light utilization efficiency and promote uniform distribution of the light field within the catalytic bed region.

4. The continuous flow photothermal catalytic reactor according to claim 1, characterized in that: The light source is one or more of the following: xenon lamp, LED array, halogen lamp, or solar simulated light source.

5. The continuous flow photothermal catalytic reactor according to claim 1, characterized in that: The catalyst bed is a fixed bed, a porous bed, or a structured catalyst bed, and is located within a uniformly illuminated area formed by the light source and the reflective sidewall.

6. The continuous flow photothermal catalytic reactor according to claim 1, characterized in that: The heat exchanger is a spiral coil heat exchanger, used to transfer the heat of the high-temperature gas after the reaction to the inlet reaction gas.

7. The continuous flow photothermal catalytic reactor according to claim 1, characterized in that: The cooling and condensation module includes a cooling coil and a condensation collection unit, which is used to reduce the temperature of the gas after the reaction and collect the liquid condensate.

8. The continuous flow photothermal catalytic reactor according to claim 1, characterized in that: The online analysis module includes one or more of a gas chromatograph, a mass spectrometer, or an infrared gas analyzer.

9. A method for operating a continuous flow photothermal catalytic reactor according to any one of claims 1 to 8, characterized in that, Includes the following steps: (1) The reaction gas enters the mixing chamber and is mixed after being regulated by a mass flow controller; (2) The mixed reaction gas enters the heat recovery preheating module, where it exchanges heat with the high-temperature gas after the reaction and completes the preheating; (3) The preheated reaction gas enters the photothermal reaction module and undergoes a continuous flow photothermal catalytic reaction under the illumination introduced by the transparent quartz window, the homogenization effect of the light field formed by the reflective sidewall, and the action of the catalytic bed. (4) After the reaction, the gas is cooled and the condensate is separated by a cooling and condensation module; (5) The cooled gas enters the online analysis module for composition detection; (6) Unreacted gas is returned to the intake mixing module via the tail gas recirculation module to continue participating in the reaction.

10. The operating method according to claim 9, characterized in that: The continuous flow photothermal catalytic reaction includes methane dry reforming or carbon dioxide hydrogenation methanation, and the catalyst bed is packed with Ni / CeO2 catalyst.

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