Solar-driven photo-thermal catalytic methanol synthesis system and control method

Abstract

This invention relates to the field of solar thermochemical utilization and industrial process control technology, specifically disclosing a solar-driven photothermal catalytic methanol synthesis system and control method. The system includes a concentrator, a photothermal catalytic reactor, a feedstock supply and flow rate regulation unit, a temperature monitoring unit for monitoring the temperature of the photothermal catalytic reactor, a DNI monitoring unit, a tracking drive mechanism for focusing solar radiation onto the focal region of the concentrator, and a control unit. This invention effectively enhances radial heat conduction and distributed heat transfer to suppress hot spots; this invention uses the input flow rate of the feedstock gas... Q in As the steady-state master control variable, the condenser offset defocus angle Δ is used. θ To assist in boundary protection / rapid energy reduction, and to propose an asymmetric strategy of "rapid decrease and slow increase" for DNI mutations, we can achieve stable and safe operation of the temperature window under variable irradiation conditions.

Description

Technical Field

[0001] This invention relates to the field of solar thermochemical utilization and industrial process control technology, and more specifically, to a solar-driven photothermal catalytic methanol synthesis system and control method. Background Technology

[0002] The methanol synthesis reaction (CO2 + H2 / H2O system) is a strongly exothermic reaction with a narrow suitable temperature window (e.g., approximately 230℃ to 260℃). Under solar conditions, DNI (Direct Normal Irradiation) fluctuates rapidly due to cloud cover, wind erosion, and tracking errors, while the reactor exhibits significant thermal inertia, leading to the following problems with existing technologies: 1) Temperature runaway and catalyst risk: When relying solely on flow rate adjustment, an increase in DNI can easily cause the temperature of the porous media catalyst bed or wall to exceed the limit, leading to catalyst sintering and deactivation; a sudden drop in DNI can easily cause the temperature of the porous media catalyst bed to drop rapidly, resulting in reaction quenching or a significant decrease in conversion rate.

[0003] 2) Kinetic and thermodynamic contradiction: Although increasing the temperature accelerates the reaction rate, it will be limited by thermodynamic equilibrium, reducing CO2 conversion and promoting the reverse water-gas shift reaction (RWGS) side reaction, thus reducing methanol selectivity.

[0004] 3) Insufficient energy regulation granularity: The concentrating system can output thermal power higher than the suitable temperature range. The traditional "full focus / full defocus" protection method is discrete and has a large impact, which can easily cause production interruption and drastic temperature fluctuations, making it difficult to achieve continuous and stable operation. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a solar-driven photothermal catalytic methanol synthesis system and its control method; The solution adopted by this invention to solve the technical problem is: A solar-driven photothermal catalytic methanol synthesis system includes a concentrating solar collector, a photothermal catalytic reactor disposed above the concentrating solar collector, a feedstock supply and flow regulation unit connected to the photothermal catalytic reactor and used for supplying feedstock gas to the photothermal catalytic reactor, a temperature monitoring unit for monitoring the temperature of the photothermal catalytic reactor, a direct normal irradiance (DNI) monitoring unit for measuring DNI, a tracking drive mechanism for focusing solar radiation onto the focal line region of the concentrating solar collector, and control units respectively connected to the feedstock supply and flow regulation unit, the temperature monitoring unit, the DNI monitoring unit, and the tracking drive mechanism; the concentrating solar collector is a trough-type concentrating solar collector, and the photothermal catalytic reactor is disposed within the groove of the trough-type concentrating solar collector.

[0006] In some possible embodiments, the photothermal catalytic reactor has a regenerative sleeve structure, including an outer tube, an inner tube coaxially fitted inside the outer tube and forming an annular gap, and a catalytic layer disposed within the annular gap; One end of the inner tube forms an outlet with the outer tube, and the other end of the inner tube is located inside the outer tube; An inlet is provided at one end of the inner tube near the outlet; the inlet and outlet are respectively connected to the raw material supply and flow regulation unit.

[0007] In some possible implementations, the raw material supply and flow regulation unit includes a conveying pipe connected to the inlet, a raw material supply system connected to the conveying pipe, a flow controller mounted on the conveying pipe, a condenser separator connected to the conveying pipe and the outlet respectively, and a storage tank connected to the condenser separator; the connection point between the condenser separator and the conveying pipe is located between the inlet and the flow controller; the end of the inner pipe away from the inlet is connected to the annular gap.

[0008] In some possible embodiments, the catalyst layer is a catalyst coated on the outside of the inner tube, or a porous media catalyst bed disposed in the annular gap; the porous media catalyst bed includes a porous medium filling the annular gap and a catalyst supported on the porous medium.

[0009] In some possible implementations, the raw material supply system stores carbon dioxide, hydrogen, or water; the molar ratio of the carbon dioxide, hydrogen, or water is 1:3-5.

[0010] on the other hand: A control method for a solar-driven photothermal catalytic methanol synthesis system as described above specifically refers to: Data monitoring to determine the type of DNI operating condition: When the DNI operating condition is stable, the feed gas input flow rate is adjusted. Q in This ensures that the temperature of the photothermal catalytic reactor remains stable within the high-efficiency temperature range; When the increase in direct radiation irradiance leads to the highest temperature of the photothermal catalytic reactor T max Exceeding the set warning threshold T warn However, the input flow rate of raw gas Q in Less than the maximum input flow limit Q max When the flow rate is 70%, control the input flow rate of the raw gas. Q in Increase the amount of heat to remove excess heat and increase the processing capacity; When the increase in direct radiation irradiance leads to the highest temperature of the photothermal catalytic reactorT max The set warning threshold has been reached. T warn And the input flow rate of raw gas Q in Reaching the maximum input flow limit Q max Adjustable defocusing is achieved through a tracking drive mechanism; When the direct radiation intensity increases, causing the maximum temperature of the photothermal catalytic reactor to exceed the safety threshold... T safe Safe defocusing is achieved through a tracking drive mechanism; If the DNI operating condition results in a cloud inflow condition, the input flow rate of the raw gas will be reduced. Q in Reduced to maintaining flow Q hold ; If cloud emergence occurs during DNI operation, gradually restore the feed gas input flow rate. Q in .

[0011] In some possible implementations, when the DNI operating condition is a stable condition, the feed gas input flow rate is adjusted. Q in This ensures that the temperature of the photothermal catalytic reactor remains stable within the high-efficiency temperature range, specifically referring to: When the highest temperature of the photothermal catalytic reactor T max Located at the target temperature T set No action is required within the specified range; When the temperature of the photothermal catalytic reactor drops and deviates from the set target temperature T set At the same time, control the input flow rate of the raw material gas. Q in The temperature is lowered to reduce sensible heat runoff and maintain the temperature of the photothermal catalytic reactor.

[0012] In some possible implementations, adjustable defocusing is achieved through a tracking drive mechanism. Specifically, the tracking drive mechanism outputs an offset angle Δθ, causing the focused light spot to shift relative to the photothermal catalytic reactor. This achieves an approximately linear reduction in incident energy flux density within a small angle range, suppressing further temperature rise in the photothermal catalytic reactor and pulling the temperature back to a safe range.

[0013] In some possible implementations, safe defocusing is achieved through a tracking drive mechanism, specifically by increasing the offset angle of the tracking drive mechanism to a safe defocus angle Δθ, thereby reducing energy input.

[0014] In some possible implementations, the gradual restoration of the feed gas input flow rate specifically refers to: The feed gas should first maintain a constant flow rate. Q hold The feed is continued until the temperature of the photothermal catalytic reactor recovers to above the ignition temperature of 200°C, then the recovery slope is maintained at ≤ 0.1. Q max The flow rate is gradually increased to the input flow rate of the raw gas. Q in .

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention employs a regenerative sleeve structure in conjunction with a multi-media catalytic bed to construct a photothermal catalytic reactor, which effectively enhances radial heat conduction and distributed heat exchange to suppress hot spots. This invention uses the input flow rate of raw gas Q in As the steady-state master control variable, the condenser offset defocus angle Δ θ To assist in boundary protection / rapid energy reduction, and to propose an asymmetric strategy of "rapid decrease and slow increase" for DNI mutations, we can achieve stable and safe operation of the temperature window under variable irradiation conditions. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a flowchart of the process of the present invention; in: 10. Concentrating solar collector; 1. Photothermal catalytic reactor; 11. Outer tube; 12. Inner tube; 13. Catalyst layer; 2. Raw material supply and flow regulation unit; 21. Raw material supply system; 22. Flow controller; 23. Condensation separator; 24. Storage tank; 3. Temperature monitoring unit; 4. DNI monitoring unit; 5. Control unit. Detailed Implementation

[0017] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. The terms "first," "second," and similar terms used in this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, "a" or "one," etc., do not indicate a quantity limitation, but rather indicate the existence of at least one. In the implementation of this application, "and / or" describes the association relationship of related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. In the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more. For example, multiple positioning posts refer to two or more positioning posts. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0018] The present invention will now be described in detail.

[0019] like Figures 1-2 As shown: A solar-driven photothermal catalytic methanol synthesis system includes a concentrator 10, a photothermal catalytic reactor 1 disposed above the concentrator 10, a feedstock supply and flow rate regulation unit 2 connected to the photothermal catalytic reactor 1 and used for supplying feedstock gas to the photothermal catalytic reactor 1, a temperature monitoring unit 3 for monitoring the temperature of the photothermal catalytic reactor 1, a direct normal irradiance (DNI) monitoring unit 4 for measuring DNI, a tracking drive mechanism for focusing solar radiation onto the focal line region of the concentrator 10, and a control unit 5 connected to the feedstock supply and flow rate regulation unit 2, the temperature monitoring unit 3, the DNI monitoring unit 4, and the tracking drive mechanism respectively; the concentrator 10 is a trough-type concentrator, and the photothermal catalytic reactor 1 is disposed within the trough of the trough-type concentrator and located at the focal line; Specifically, the tracking drive mechanism works in conjunction with the concentrator 10, and under the control of the control unit 5, it focuses solar radiation onto the focal line region, and can generate a controllable bias angle Δ under the command of the control unit 5. θ Achieve defocusing; The raw material supply and flow regulation unit 2 is used to proportion CO2 and H2 and to regulate the output intake flow rate. Q in To take control; Temperature monitoring unit 3 is used to monitor the temperature of photothermal catalytic reactor 1 and the temperature of the porous media catalytic bed inside photothermal catalytic reactor 1, and transmit the data to control unit 5; DNI monitoring unit 4 monitors the normal direct radiation irradiance and transmits the data to control unit 5. Control unit 5 analyzes the data and determines the type of DNI operating condition. Based on the type, it adjusts the actual input flow rate of the raw gas or adjusts the offset angle through the tracking drive mechanism to achieve stable and safe operation of the temperature window under variable irradiance conditions.

[0020] The photothermal catalytic reactor 1 is located at the focal line of the concentrating solar collector 10; the photothermal catalytic reactor 1 has a regenerative sleeve structure; it includes an outer tube 11, an inner tube 12 coaxially fitted inside the outer tube 11 and forming an annular gap, and a catalytic layer 13 disposed in the annular gap; One end of the inner tube 12 forms an outlet with the outer tube 11, and the other end of the inner tube 12 is located inside the outer tube 11; An inlet is provided at one end of the inner tube 12 near the outlet; the inlet and outlet are respectively connected to the raw material supply and flow regulation unit 2. Specifically, the raw material gas enters the inner tube 12 through the inlet and flows, and is preheated by the catalyst layer in the annular gap. Then, it is reversed through the outlet and enters the annular gap. The raw material gas entering the inner tube 12 acts as an "in-situ cooling / regenerative carrier", which helps to improve the controllability and anti-disturbance ability of the catalyst layer 13 temperature when the direct normal irradiance fluctuates. The catalytic layer 13 allows the heat input to the wall of the outer tube 11 to diffuse rapidly under the action of the catalytic layer 13, thereby reducing local hot spots and axial temperature differences.

[0021] In some possible implementations, the raw material supply and flow regulation unit 2 includes a conveying pipe connected to the inlet, a raw material supply system 21 connected to the conveying pipe, a flow controller 22 mounted on the conveying pipe, a condenser 23 connected to the conveying pipe and the outlet respectively, and a storage tank 24 connected to the condenser 23; the connection point between the condenser 23 and the conveying pipe is located between the inlet and the flow controller 22; the end of the inner pipe 12 away from the inlet is connected to the annular gap; Preferably, heat dissipation fins are provided inside the inner tube 12 to accelerate heat exchange; The raw material supply system 21 is used to supply raw material gas, and the flow controller 22 realizes real-time monitoring and control of the input flow of raw material gas into the inner pipe 12; The feed gas undergoes reheating and preheating and annular reaction in the photothermal catalytic reactor 1. The product after the reaction flows through the outlet to the condenser separator 23 to obtain methanol liquid product, which will be stored in the storage tank 24.

[0022] In some possible embodiments, the catalyst layer 13 is a catalyst coated on the outside of the inner tube, or a porous media catalyst bed disposed in the annular gap; the porous media catalyst bed includes a porous medium filling the annular gap and a catalyst supported on the porous medium; Preferably, the porous medium has good thermal conductivity, such as any one of foamed metal, foamed ceramic, alumina, foamed nickel, or foamed aluminum; through the radial thermal conductivity and large specific surface area heat transfer characteristics of the porous medium, the heat input from the wall can be rapidly diffused in the bed, reducing local hot spots and axial temperature differences.

[0023] In some possible implementations, the raw material supply system 21 stores a mixture of carbon dioxide, hydrogen, or water; the molar ratio of the carbon dioxide, hydrogen, or water is 1:3-5.

[0024] on the other hand: A control method for a solar-driven photothermal catalytic methanol synthesis system as described above specifically refers to: Data monitoring to determine the type of DNI operating condition: Specifically, data monitoring includes direct irradiance monitored by DNI monitoring unit 4, temperature at multiple points within the photothermal catalytic reactor 1 monitored by temperature monitoring unit 3, and feed gas input flow rate. Q in The control unit 5 obtains the highest temperature of the photothermal catalytic reactor 1 based on the temperature at multiple points. T max ; Determining the type of DNI operating condition specifically refers to comparing the direct irradiance with the DNI threshold. The types of DNI operating conditions include cloud entry condition, cloud exit condition, and stable condition. When the DNI operating condition is stable, the feed gas input flow rate is adjusted. Q in This ensures that the temperature of the photothermal catalytic reactor 1 remains stable within the high-efficiency temperature range; specifically including: When the increase in direct radiation irradiance leads to the highest temperature of photothermal catalytic reactor 1 T max Located at the target temperature T set Within the specified range, no action is required; specifically, the target temperature. T set ≤ 230℃ T set <260℃; that is: T max Between 230℃ and 260℃.

[0025] When the highest temperature T maxThe temperature dropped below the set target temperature. T set When the flow rate of raw material gas is controlled within a certain range, the input flow rate of the raw material gas is controlled. Q in The temperature is reduced to decrease the sensible heat runoff and maintain the temperature of the photothermal catalytic reactor 1.

[0026] When the increase in direct radiation irradiance leads to the highest temperature T max The set warning threshold has been reached. T warn Warning threshold T warn The temperature is 260℃, but the input flow rate of the raw gas is... Q in Less than the maximum input flow limit Q max When the flow rate is 70%, control the input flow rate of the raw gas. Q in Increase the amount of heat to remove excess heat and increase the processing capacity; When the increase in direct radiation irradiance leads to the highest temperature T max The set warning threshold has been reached. T warn And the input flow rate of raw gas Q in Reaching the maximum input flow limit Q max When the focus reaches 70%, control unit 5 adjusts the defocus via the tracking drive mechanism; specifically: The control unit 5 controls the output bias angle Δθ of the tracking drive mechanism, causing the focused light spot to shift relative to the photothermal catalytic reactor 1. This achieves an approximately linear reduction in the incident energy flux density within a small angle range, suppressing the temperature of the photothermal catalytic reactor 1 from continuing to rise and pulling the temperature of the photothermal catalytic reactor 1 back to a safe range. The small angle range described here is 0.5° to 5°.

[0027] When the increase in direct radiation irradiance leads to the highest temperature of photothermal catalytic reactor 1 T max Exceeding the set security threshold T safe Safe defocusing is achieved through a tracking drive mechanism; safety threshold T safe 280℃, specifically refers to: Control unit 5 increases the offset angle Δ through the tracking drive mechanism. θ To achieve a safe defocus angle, reduce energy input and, in conjunction with this, reduce the input flow rate of the raw material gas. Q in Or trigger the protection shutdown logic; preferably, the safe defocus angle is ≥15°.

[0028] The following asymmetric strategy is employed to address DNI mutations: If the DNI operating condition results in a cloud inflow condition, the input flow rate of the raw gas will be reduced. Q in Reduced to the set maintenance flow rate Q hold To avoid the reactor 1 being "cooled down" by a large flow rate, which could cause it to shut down; If cloud emergence occurs during DNI operation, a delayed input flow recovery strategy is adopted, that is, gradually restoring the input flow of raw gas. Specifically, this means: The feed gas should first maintain a constant flow rate. Q hold Transport for a period of time, maintain flow Q hold Lower than input flow Q in Until the temperature of the photothermal catalytic reactor 1 recovers to above the ignition temperature of 200°C, then the recovery slope is ≤ 0.1. Q max The flow rate is gradually increased to the input flow rate of the raw gas. Q in .

[0029] This cycle is repeated to achieve temperature window control and safety boundary protection under all-weather variable irradiance conditions.

[0030]

Example 1

[0031] The concentrator is a slotted concentrator with an opening width of 1 m, a length of 4 m, and an edge angle of 80°. The photothermal catalytic reactor adopts a regenerative sleeve structure with an outer tube diameter of 50 mm, an inner tube diameter of 25 mm, and a length of 3.8 m. The catalyst layer is a porous media catalyst bed, which uses copper foam as a framework with a porosity of 85% and a pore density of 20 ppi. The catalyst is Ru / In₂O₃, with Ru loading of 2 wt%. The feed gas is a mixture of CO2 and H2 with a molar ratio of 1:3 and an inlet temperature of 25°C.

[0032] The control parameters are set as follows: target temperature T set The warning threshold is 245 °C. T warn The safe threshold is 260 °C. T safeThe maximum upper limit of the feed gas input flow rate is 280°C. Q max The flow rate is 100 L / min, and the maintenance flow rate is maintained. Q hold The flow rate is 25 L / min, which is 0.25 × Q max The maximum flow recovery slope during the cloud recovery phase is 5 L / min per minute.

[0033] Operating procedure: Under clear weather conditions, i.e., DNI is approximately 800~900 W / m 2 ; During normal system operation, the raw gas input flow rate Q in The flow rate was stabilized at 60-80 L / min, and the temperature of the porous media catalytic bed was maintained in the range of 240-250 °C.

[0034] When cloud cover causes a rapid decrease in DNI, i.e., the rate of change exceeds -50 W / (m²),... 2 ·s) lasting 3 seconds, the control unit recognizes the cloud access condition and quickly reduces the flow rate to a maintenance flow rate of 25 L / min; Once the clouds have dispersed, the DNI (Discharge Noise Reduction) system resumes operation. The control unit recognizes the operation as cloud emergence and gradually restores the flow rate at a rate of 5 L / min after the catalytic bed temperature rises above 200°C.

[0035] Using the system and control method of this embodiment, the maximum temperature fluctuation of the photothermal catalytic reactor can be controlled within ±20 °C when the DNI fluctuation range reaches 30%, effectively avoiding the reaction quenching caused by overheating sintering or excessively low temperature.

[0036] This invention is not limited to the specific embodiments described above. The invention extends to any new feature or combination disclosed in this specification, as well as any new method or process step or combination disclosed herein.

Claims

1. A solar-driven photothermal catalytic methanol synthesis system, characterized in that, The system includes a concentrating solar collector, a photothermal catalytic reactor positioned above the concentrating solar collector, a feedstock supply and flow regulation unit connected to the photothermal catalytic reactor and used for supplying feedstock gas to the photothermal catalytic reactor, a temperature monitoring unit for monitoring the temperature of the photothermal catalytic reactor, a direct normal irradiance (DNI) monitoring unit for measuring the direct normal irradiance (DNI), a tracking drive mechanism for focusing solar radiation onto the focal line region of the concentrating solar collector, and control units connected to the feedstock supply and flow regulation unit, the temperature monitoring unit, the DNI monitoring unit, and the tracking drive mechanism, respectively; the concentrating solar collector is a trough-type concentrating solar collector, and the photothermal catalytic reactor is disposed within the groove of the trough-type concentrating solar collector.

2. The solar-driven photothermal catalytic methanol synthesis system according to claim 1, characterized in that, The photothermal catalytic reactor has a regenerative sleeve structure, including an outer tube, an inner tube coaxially fitted inside the outer tube to form an annular gap, and a catalytic layer disposed within the annular gap; One end of the inner tube forms an outlet with the outer tube, and the other end of the inner tube is located inside the outer tube; An inlet is provided at one end of the inner tube near the outlet; the inlet and outlet are respectively connected to the raw material supply and flow regulation unit.

3. The solar-driven photothermal catalytic methanol synthesis system according to claim 2, characterized in that, The raw material supply and flow regulation unit includes a conveying pipe connected to the inlet, a raw material supply system connected to the conveying pipe, a flow controller installed on the conveying pipe, a condenser connected to the conveying pipe and the outlet respectively, and a storage tank connected to the condenser; the connection point between the condenser and the conveying pipe is located between the inlet and the flow controller; the end of the inner pipe away from the inlet is connected to the annular gap.

4. The solar-driven photothermal catalytic methanol synthesis system according to claim 2, characterized in that, The catalyst layer is a catalyst coated on the outside of the inner tube, or a porous media catalyst bed set in the annular gap; The porous media catalytic bed includes a porous media filling the annular gap and a catalyst supported on the porous media.

5. The solar-driven photothermal catalytic methanol synthesis system according to claim 2, characterized in that, The raw material supply system stores carbon dioxide, hydrogen, or water; the molar ratio of the carbon dioxide, hydrogen, or water is 1:3-5.

6. A control method for a solar-driven photothermal catalytic methanol synthesis system according to any one of claims 1-5, characterized in that, Specifically, it refers to: Data monitoring to determine the type of DNI operating condition: When the DNI operating condition is stable, the feed gas input flow rate is adjusted. Q in This ensures that the temperature of the photothermal catalytic reactor remains stable within the high-efficiency temperature range; When the increase in direct radiation irradiance leads to the highest temperature of the photothermal catalytic reactor T max Exceeding the set warning threshold T warn However, the input flow rate of raw gas Q in Less than the maximum input flow limit Q max When the flow rate is 70%, control the input flow rate of the raw gas. Q in Increase the amount of heat to remove excess heat and increase the processing capacity; When the increase in direct radiation irradiance leads to the highest temperature of the photothermal catalytic reactor T max The set warning threshold has been reached. T warn And the input flow rate of raw gas Q in Reaching the maximum input flow limit Q max Adjustable defocusing is achieved through a tracking drive mechanism; When the direct radiation intensity increases, causing the maximum temperature of the photothermal catalytic reactor to exceed the safety threshold... T safe Safe defocusing is achieved through a tracking drive mechanism; If the DNI operating condition results in a cloud inflow condition, the input flow rate of the raw gas will be reduced. Q in Reduced to maintaining flow Q hold ; If cloud emergence occurs during DNI operation, gradually restore the feed gas input flow rate. Q in .

7. The control method for a solar-driven photothermal catalytic methanol synthesis system according to claim 6, characterized in that, When the DNI operating condition is stable, the feed gas input flow rate is adjusted. Q in This ensures that the temperature of the photothermal catalytic reactor remains stable within the high-efficiency temperature range, specifically referring to: When the highest temperature of the photothermal catalytic reactor T max Located at the target temperature T set No action is required within the specified range; When the temperature of the photothermal catalytic reactor drops and deviates from the set target temperature T set At the same time, control the input flow rate of the raw material gas. Q in The temperature is lowered to reduce sensible heat runoff and maintain the temperature of the photothermal catalytic reactor.

8. The control method for a solar-driven photothermal catalytic methanol synthesis system according to claim 6, characterized in that, Adjustable defocusing via a tracking drive mechanism specifically refers to the tracking drive mechanism outputting an offset angle Δθ, causing the focused light spot to shift relative to the photothermal catalytic reactor. This achieves an approximately linear reduction in incident energy flux density within a small angle range, suppressing further temperature rise in the photothermal catalytic reactor and pulling the temperature back to a safe range.

9. The control method for a solar-driven photothermal catalytic methanol synthesis system according to claim 6, characterized in that, Safe defocusing via a tracking drive mechanism specifically refers to increasing the offset angle of the tracking drive mechanism to a safe defocusing angle Δθ, thereby reducing energy input.

10. The control method for a solar-driven photothermal catalytic methanol synthesis system according to claim 6, characterized in that, The gradual restoration of the feed gas input flow rate specifically refers to: The feed gas should first maintain a constant flow rate. Q hold The feed is continued until the temperature of the photothermal catalytic reactor recovers to above the ignition temperature of 200°C, then the recovery slope is maintained at ≤ 0.

1. Q max The flow rate is gradually increased to the input flow rate of the raw gas. Q in .

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