Biomass pyrolytic reaction device and method based on solar thermal driving

Abstract

The invention relates to the technical field of energy utilization and biomass pyrolysis reactors, in particular to a biomass pyrolysis reaction device and method. The device comprises a biomass pyrolysis reactor and a circulating heat conduction assembly, and the biomass pyrolysis reactor and the circulating heat conduction assembly are connected through a heat supply pipe and a heat return pipe to form a heat supply circulating pipeline; the heat supply pipe is provided with a heat supply valve, and the heat return pipe is provided with a heat return valve for opening and closing a heat supply and heat return passage. The circulation heat conduction assembly comprises a heat supply box, a heat exchange box and heating equipment. The heat supply box and the heat exchange box are connected through a first guide pipe and a second guide pipe to form a heating circulation pipeline. The heating device is installed on the first guide pipe to heat the heat-conducting medium, the first guide pipe is provided with an air inlet for introducing inert gas and leading to the heat supply box, and the second guide pipe is provided with a heating circulating valve. The device further comprises a control system used for detecting the temperature of the heat supply circulation pipeline and the temperature of the heating circulation pipeline and regulating and controlling opening and closing of all the valves, switching of the two circulation pipelines is achieved, and therefore controllable switching of heat conduction medium preheating circulation and heat supply circulation is achieved.

Description

Technical Field

[0001] This invention relates to the field of energy utilization and biomass pyrolysis reactor technology, specifically to a solar thermal-driven biomass pyrolysis reactor and method. Background Technology

[0002] Biomass, as the only renewable and clean carbon source, can be directly converted into high-quality liquid fuels through thermochemical conversion, reducing dependence on non-renewable fossil fuels such as petroleum. Biomass pyrolysis is a thermochemical conversion technology that transforms biomass into pyrolysis gas, pyrolysis oil, and pyrolysis char under high-temperature, oxygen-deficient, or anaerobic conditions. However, the biomass pyrolysis process requires energy to heat the biomass to the appropriate reaction temperature, and its complexity leads to poor product selectivity, affecting subsequent utilization.

[0003] Solar energy is one of the most readily available clean energy sources, but its energy density is relatively low, requiring methods such as concentrating to improve its density and quality. Biomass has poor thermal conductivity and low solar energy absorption, necessitating the use of heat-conducting media for energy transfer. However, leakage of high-temperature heat-conducting media and losses in high-temperature pumps limit the large-scale application of solar energy in biomass thermal utilization. Industrial waste heat is diverse, and its ineffective utilization leads to energy waste. Applying low-density energy sources like solar energy or industrial waste heat to biomass thermochemical conversion can not only improve energy utilization efficiency and recover low-quality energy, but also enable the production of high-quality fuels from biomass pyrolysis.

[0004] Currently, molten salt systems are already applied in the field of pyrolysis. Patent CN104399732B provides a method for molten salt pyrolysis of solid waste. This method uses molten salt as a pyrolysis medium, immersing solid waste in the molten salt. Under set pyrolysis conditions, the solid waste is effectively dissociated and decomposed, allowing for the recovery of various resource substances. The pyrolysis products of the organic components in the solid waste are recycled as energy and resource substances. However, the quality of the molten salt in this method is affected by the waste, making it difficult to regenerate and recycle. Patent CN114806623B proposes a fluidized bed reactor and system for producing bio-oil from biomass through molten salt pyrolysis and gasification, but it also suffers from the problem of the molten salt quality gradually deteriorating with the reaction.

[0005] Regarding solar-driven pyrolysis reaction systems, patent CN117604237A proposes a solar-driven process for co-producing hydrogen and recovering metals through circuit board pyrolysis. This process uses a tower-type solar concentrator to heat the molten salt, reducing energy consumption and carbon emissions, saving costs, and enabling rapid pyrolysis of waste circuit boards. However, direct contact between the molten salt and reactants affects the quality of the molten salt. Furthermore, the tower-type solar concentrator system requires a certain height for installation, and the circulation of the molten salt requires a high-temperature pump, which poses a risk of leakage of the high-temperature heat transfer medium.

[0006] Regarding multi-quality heat source driven pyrolysis, patent CN120775605A proposes a coal pyrolysis reactor with multi-source heat carrier heat transfer. The heat carrier is a molten metal salt, which exchanges heat with the coal to be pyrolyzed through an indirect heat exchange mechanism, effectively avoiding the problem of heat carrier quality deterioration during the reaction. Heat recovery and multi-quality heat utilization are achieved through the circulation of the molten metal salt. However, the circulation driving problem of the high-temperature heat carrier is unclear, and risks such as leakage of high-temperature heat transfer medium or high-temperature pump loss still exist. Summary of the Invention

[0007] The technical objective of this invention is: To achieve the above-mentioned technical objectives, the present invention provides the following technical solution: The present invention provides a solar thermal driven biomass pyrolysis reactor, comprising a biomass pyrolysis reactor and a circulating heat conduction component, wherein the biomass pyrolysis reactor and the circulating heat conduction component are connected by a heating pipe and a heat return pipe to form a heating circulation pipeline. The heating pipe is equipped with a heating valve for opening and closing the heating passage from the circulating heat conduction component to the biomass pyrolysis reactor; the heat recovery pipe is equipped with a heat recovery valve for opening and closing the heat recovery passage from the biomass pyrolysis reactor to the circulating heat conduction component. Furthermore, the circulating heat conduction assembly includes a heating box, a heat exchange box, and a heating device, wherein the heating box and the heat exchange box are connected by a first conduit and a second conduit to form a heating circulation pipeline; Preferably, the heating device is installed on the first conduit and is used to heat the heat-conducting medium inside the first conduit; Furthermore, an air inlet is also installed on the first conduit, the air inlet being used to introduce inert gas into the first conduit; the inert gas flows into the heating box within the first conduit; The second conduit is used to connect the heat transfer medium from the heating box to the heat exchange box, and a heating circulation valve is provided on it. It also includes a control system for switching between the hot circulation pipeline and the heating circulation pipeline by detecting the temperature of the hot circulation pipeline and the heating circulation pipeline and then regulating the opening and closing of each valve.

[0008] Furthermore, the biomass pyrolysis reactor is connected to the heating pipe and the regenerating pipe via a heat exchange tube; the heat exchange tube is sleeved on the outside of the biomass pyrolysis reactor, and the heat exchange tube exchanges heat with the biomass pyrolysis reactor through the heat-conducting medium flowing inside it; the upper end of the heat exchange tube is connected to the heating pipe, and the lower end is connected to the regenerating pipe.

[0009] Preferably, the biomass pyrolysis reactor has multiple exhaust layers distributed along the axial direction of the heat exchange tubes; each exhaust layer is connected to an exhaust port.

[0010] More preferably, the exhaust port is provided with a biomass pyrolysis catalyst, which is one of iron-based, zirconium-based, aluminum-based, or molecular sieve catalysts.

[0011] Preferably, the heat-conducting medium is an organic heat-conducting oil or a molten salt.

[0012] The present invention also provides a biomass pyrolysis reaction method, applicable to the above-mentioned apparatus, characterized by comprising the following steps: Close the heating valve and the regenerative valve, open the heating circulation valve, add the heat transfer medium to the heating box, and add biomass raw materials to the biomass pyrolysis reactor. The heating equipment is turned on to heat the first conduit at a constant heating rate, while inert gas is introduced into the first conduit at a constant flow rate through the air inlet. The inert gas flows through the first conduit to the heating box. An inert gas and a heat-conducting medium in the first conduit form a mixed medium, which is then heated and circulated in the heating circulation pipeline. Once the mixed medium in the heating circulation pipeline reaches the set temperature, the heating valve and the regeneration valve are opened, and the heating circulation valve is closed; the mixed medium enters the heating circulation pipeline and exchanges heat with the biomass pyrolysis reactor. Wait for the biomass pyrolysis reactor to pyrolyze the biomass feedstock, and open the exhaust port on the biomass pyrolysis reactor to collect pyrolysis gas and bio-oil; After pyrolysis, the heating equipment, heating valve and regenerative valve are turned off, and the heating circulation valve is turned on. The mixed medium is cooled and circulated in the heating circulation pipeline. The biomass pyrolysis reactor is cooled naturally. After the temperature of the mixed medium drops to room temperature, the air inlet is closed.

[0013] In a preferred reaction method, the heat-conducting medium is an organic heat-conducting oil; the inert gas is nitrogen; and the biomass raw material is poplar wood chips with a particle size of 80-100 mesh. The constant flow rate is 70 mL / min; the set temperature is 320 °C.

[0014] In a preferred reaction method, the heat-conducting medium is a ternary molten salt with a mass fraction of 40% NaNO2, 7% NaNO3 and 53% KNO3, a melting point of 142-148℃ and a boiling point of 680℃; the inert gas is nitrogen; and the biomass raw material is poplar wood chips with a particle size of 80-100 mesh. The constant flow rate is 100 mL / min; the set temperature is 520 °C.

[0015] The beneficial effects of this invention are as follows: 1. This invention sets up a biomass pyrolysis reactor and a circulating heat transfer assembly, and forms a heating circulation pipeline with heating pipes and regenerating pipes. At the same time, heating valves and regenerating valves are respectively set on the heating pipes and regenerating pipes, and a heating circulation pipeline is constructed between the heating box and the heat exchange box. Inert gas is introduced through the gas inlet at a constant flow rate and forms a mixed medium with the liquid phase heat transfer medium in the pipeline. The mixed medium completes uniform heating during the circulation process and enters the heating circulation pipeline to exchange heat stably with the pyrolysis reactor after reaching the set temperature. Thus, the pyrolysis heating process is continuous, the heating rate is controllable, and the heat input fluctuation is small.

[0016] 2. The present invention further connects the biomass pyrolysis reactor to the heating pipe and the regenerating pipe through a heat exchange tube, and the heat exchange tube is sleeved on the outside of the reactor. The heat-conducting medium circulating inside the heat exchange tube is used to indirectly exchange heat with the reactor wall. The upper end of the heat exchange tube is connected to the heating pipe and the lower end is connected to the regenerating pipe, so that the heat-conducting medium forms a stable heat exchange path along the reactor axis. This can significantly increase the effective heat exchange area and improve the heat transfer uniformity, and reduce the temperature difference of the reactor wall and the probability of hot spot formation.

[0017] 3. In this invention, multiple exhaust layers are set up in the biomass pyrolysis reactor along the axial direction of the heat exchange tube, and each exhaust layer is connected to an exhaust port. At the same time, a biomass pyrolysis catalyst is set in the exhaust port. During the pyrolysis process, volatiles can be discharged in stages at different axial positions, reducing the residence time of volatiles in the high-temperature zone and the secondary cracking caused by it, thereby improving the collection efficiency and quality stability of pyrolysis gas and bio-oil. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] The above and other aspects of the invention will now be described by way of example only, with reference to the accompanying drawings, in which: Figure 1This is a schematic diagram of the overall structure of the device of the present invention; Figure 2 This is a schematic diagram of the specific component composition of the device of the present invention; Figure 3 This is a temperature field distribution diagram of the organic heat transfer oil during the operation of the device of the present invention; Figure 4 This is a temperature field distribution diagram of molten salt during the operation of the device of the present invention.

[0020] In the diagram: 1. Biomass pyrolysis reactor; 11. Heat exchanger tube; 12. Exhaust layer; 13. Exhaust port; 2. Circulating heat conduction assembly; 21. Heating box; 22. Heat exchanger box; 23. Heating equipment; 24. First conduit; 25. Second conduit; 26. Air inlet; 27. Heating circulation valve; 3. Heating pipe; 4. Regenerating pipe; 5. Heating valve; 6. Regenerating valve; 7. Control system. Detailed Implementation

[0021] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0022] This invention proposes a solar thermal-driven biomass pyrolysis reactor device, comprising a biomass pyrolysis reactor 1 and a circulating heat transfer assembly 2. The biomass pyrolysis reactor 1 and the circulating heat transfer assembly 2 are connected by a heating pipe 3 and a heat return pipe 4 to form a heating circulation pipeline. A heating valve 5 is provided on the heating pipe 3 for opening and closing the heating passage from the circulating heat transfer assembly 2 to the biomass pyrolysis reactor 1. A heat return valve 6 is provided on the heat return pipe 4 for opening and closing the heat return passage from the biomass pyrolysis reactor 1 to the circulating heat transfer assembly 2. The circulating heat transfer assembly 2 includes a heating box 21 and a heat exchanger. The heating box 22 and the heating device 23 are connected by a first conduit 24 and a second conduit 25 to form a heating circulation pipeline. The heating device 23 is installed on the first conduit 24 and is used to heat the heat transfer medium in the first conduit 24. An air inlet 26 is also installed on the first conduit 24 for introducing inert gas into the first conduit 24. The inert gas is introduced into the heating box 21 in the first conduit 24. The second conduit 25 is used to connect the heat transfer medium from the heating box 21 to the heat exchange box 22, and a heating circulation valve 27 is provided on it. It also includes a control system 7, which is used to switch between the heat circulation pipeline and the heating circulation pipeline by detecting the temperature of the heat supply circulation pipeline and the heating circulation pipeline and then regulating the opening and closing of each valve.

[0023] The heating circulation pipeline is used to heat the heat transfer medium before the heating cycle and form a stable circulating heat exchange condition. The heating circulation pipeline is used to introduce the heat-carrying medium into the biomass pyrolysis reactor 1 side after the valve is switched to achieve reaction heating. The control system 7 performs linkage control on the temperature detection results of the two circulation pipelines to realize the switching logic between the heating valve 5, the regeneration valve 6 and the heating circulation valve 27, so that the switching process of the heat transfer medium between the heating cycle and the heating cycle is controllable, thereby reducing the temperature fluctuation of the heating process and improving the stability of the pyrolysis reaction. The inert gas enters from the inlet 26 and is led to the heating box 21 through the first conduit 24, so that an inert environment is formed synchronously during the heating cycle stage, which is beneficial to suppressing unwanted oxidation side reactions and reducing the risk of coking.

[0024] It should be noted that the heating device 23 of the present invention uses renewable energy to heat the first conduit 24. In a specific embodiment, the heating device 23 is driven by solar energy for heating. By introducing inert gas to reduce the density of the heat transfer medium in the first conduit 24, the low-temperature heat transfer medium in the biomass pyrolysis reactor 1 flows downward, completing the circulation of the heat transfer medium. The indirect heat exchanger continuously provides heat to the biomass pyrolysis reactor 1 without affecting the quality of the heat transfer medium, avoiding the problems of heat transfer medium leakage and high-temperature pump loss. The biomass pyrolysis reactor 1 adopts a jacketed multi-section structure. In this embodiment, a three-section structure is adopted, including three exhaust ports 13: upper, middle, and lower. Each exhaust port 13 is controlled by an exhaust valve. According to the temperature change of the heat transfer medium distributed axially in the outer heat exchange tube 11, corresponding catalysts can be filled in different parts of the biomass pyrolysis reactor 1. Specifically, one of iron-based, zirconium-based, aluminum-based, and molecular sieve catalysts can be selected. By placing different catalysts in the exhaust ports 13 corresponding to different temperature layers, the quality of biomass pyrolysis oil at each temperature state is improved, and the directional pyrolysis of biomass to prepare liquid fuel is completed.

[0025] The reaction apparatus of the present invention includes the following two specific embodiments of the reaction method. Example

[0026] This embodiment provides a biomass pyrolysis reaction method based on a solar thermal-driven biomass pyrolysis reactor, using organic heat transfer oil as the circulating medium. The method includes the following steps: First, keep the heating valve 5 and the regenerative valve 6 closed, and the heating circulation valve 27 open. Continuously add fully synthetic organic heat transfer oil to the reactor through the heating tank 21. Once the liquid level reaches the designated position in the heating tank 21, add 5g of dried poplar wood chips with a particle size of 80-100 mesh into the biomass pyrolysis reactor 1. Close the exhaust ports 13 of each exhaust layer 12. Turn on the heating equipment 23 to heat the first conduit 24. Simultaneously, introduce high-purity nitrogen gas as an inert gas through the air inlet 26 at a flow rate of 70mL / min to reduce the density of the organic heat transfer oil in the first conduit 24, causing the low-temperature organic heat transfer oil in the second conduit 25 to flow downwards, forming a heating cycle of the organic heat transfer oil between the first conduit 24, the heating tank 21, the second conduit 25, and the heat exchange tank 22.

[0027] It should be noted that the biomass raw materials can be selected according to the requirements. In this application, poplar wood chips with a particle size of 80-100 mesh are selected, and the amount used can be flexibly selected according to the capacity of the device. The 5g in this application is only one implementation scheme of the embodiment. In addition, since the heat transfer medium in this embodiment is organic heat transfer oil, and the working temperature range of heat transfer oil is 200℃ to 350℃, this embodiment has optimized the working temperature range by pyrolysis reaction method. The performance of organic heat transfer oil at the optimized temperature has been analyzed by temperature field distribution diagram. Therefore, the working set temperature of the organic heat transfer oil is specifically selected as 320℃.

[0028] When the temperature of the organic heat transfer oil rises and stabilizes at 320℃, the heating valve 5 and the regeneration valve 6 are opened, and the heating circulation valve 27 is closed, switching the circulation loop of the organic heat transfer oil to the first conduit 24, the heating box 21, the heat exchange tube 11, and the heat exchange box 22, thereby realizing the pyrolysis of the biomass raw material. The pyrolysis time is 30 minutes. At this time, the exhaust port 13 is opened to collect the pyrolysis gas and bio-oil. After the pyrolysis is completed, the heating equipment 23, the heating valve 5, and the regeneration valve 6 are closed. The high-temperature organic heat transfer oil begins to circulate for cooling between the first conduit 24, the heating box 21, the second conduit 25, and the heat exchange box 22. The biomass pyrolysis reactor 1 is allowed to cool down naturally. After the organic heat transfer oil drops to room temperature, the air inlet 26 is closed.

[0029] Temperature field of organic heat transfer oil, such as Figure 3As shown, during the actual operation of this embodiment, the highest circulating temperature of the organic heat transfer oil reached 327.8℃, and the maximum temperature difference was 62.2℃. 2.25g of bio-oil was obtained from the condensation collection device, and 1.29g of biochar was obtained from biomass pyrolysis reactor 1. The total yield of pyrolysis gas was obtained by integrating data from an online gas analyzer. Based on the raw material mass calculation, the mass yields of bio-oil, biochar, and pyrolysis gas were 45.0 wt.%, 25.8 wt.%, and 29.2 wt.%, respectively. The collected bio-oil was analyzed by GC-MS, and its main chemical components and relative contents are shown in the table below:

[0030] This embodiment verifies that the reaction device can effectively drive the circulation of organic heat transfer oil, realize stable and controllable pyrolysis of biomass, and obtain bio-oil products mainly composed of high-value-added oxygen-containing compounds by effectively collecting and analyzing the biomass pyrolysis products. Example

[0031] Based on Embodiment 1, this embodiment provides a biomass pyrolysis reaction method based on a solar thermal driven biomass pyrolysis reactor, using molten salt as the circulating medium, including the following steps: First, keep the heating valve 5 and the regeneration valve 6 closed and the heating circulation valve 27 open, and continuously add ternary molten salt (composed of 40% NaNO2, 7% NaNO3, and 53% KNO3 by mass fraction, melting point 142-148℃, boiling point 680℃) to the device through the heating box 21. After the molten salt reaches the designated position in the heating box 21, load 5g of dried poplar wood chips with a particle size of 80-100 mesh into the biomass pyrolysis reactor 1, and close all exhaust ports 13.

[0032] The heating device 23 is turned on to heat the first conduit 24. After the system temperature exceeds 150°C and the molten salt is completely melted into a liquid state, high-purity nitrogen gas is introduced through the air inlet 261 at a flow rate of 100 mL / min as an inert gas to reduce the density of the molten salt in the first conduit 24, causing the low-temperature molten salt in the second conduit 25 to flow downward, thus forming a heating cycle of molten salt between the first conduit 24, the heating box 21, the second conduit 25, and the regenerating box.

[0033] Based on the above, similarly, the preferred setting temperature for the molten salt in this embodiment is 520°C. When the molten salt temperature rises and stabilizes at the set temperature of 520°C, the heating valve 5 and the regeneration valve 6 are opened, switching the circulation loop of the molten salt to the first conduit 24, the heating box 21, the heat exchange tube 11, and the regeneration box, thereby achieving the pyrolysis of the biomass raw material. The pyrolysis time is 30 minutes. At this time, the exhaust port 13 is opened to collect the pyrolysis gas and bio-oil. After the pyrolysis is completed, the heating equipment 23, the heating valve 5, and the regeneration valve 6 are turned off. The high-temperature molten salt begins to circulate for cooling between the first conduit 24, the heating box 21, the second conduit 25, and the regeneration box, and the biomass pyrolysis reactor 1 undergoes natural cooling.

[0034] To prevent the molten salt from solidifying and clogging the pipeline during the cooling process, when the system temperature drops to 250℃, first close the air inlet 26, then open the drain valve located at the bottom of the regenerator to drain all the liquid molten salt and collect it in a special container for subsequent reuse.

[0035] Temperature field of molten salt as Figure 4 As shown, during the actual operation of this embodiment, the highest circulating temperature of the molten salt reached 532.3℃, and the maximum temperature difference was 87.2℃. 2.47g of bio-oil was obtained from the condensation collection device, and 1.06g of biochar was obtained from pyrolysis reactor 6. The total yield of pyrolysis gas was obtained by integrating data from an online gas analyzer. Based on the raw material mass calculation, the mass yields of bio-oil, biochar, and pyrolysis gas were 49.4 wt.%, 21.2 wt.%, and 29.4 wt.%, respectively. The collected bio-oil was analyzed by GC-MS, and its main chemical components and relative contents are shown in the table below:

[0036] This embodiment demonstrates that using molten salt with a high boiling point and high thermal stability as a heat transfer medium can raise the biomass pyrolysis temperature to 500°C. The high temperature enhances deoxygenation and condensation reactions, increasing the total proportion of high-value phenols and aromatics in the bio-oil. Simultaneously, timely discharge of the molten salt effectively avoids pipeline blockage.

[0037] The description herein is provided to enable those skilled in the art to implement or use the present disclosure. Various modifications to the present disclosure will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other variations without departing from the scope of the disclosure. Therefore, this disclosure is not limited to the examples and designs described herein, but should be given the broadest scope consistent with the principles and novel features disclosed herein.

[0038] Although one or more exemplary embodiments of this disclosure have been described with reference to the accompanying drawings, those skilled in the art will understand that various changes in form and detail may be made therein without departing from the spirit and scope of this disclosure as defined by the appended claims.

[0039] The foregoing description is merely illustrative of this disclosure, and modifications may be made to the invention in light of the above detailed description. The terminology used in the appended claims should not be construed as limiting the invention to the specific embodiments disclosed in the specification. Rather, the scope of the invention will be fully defined by the appended claims, which will be interpreted according to established principles of claim interpretation.

Claims

1. A solar thermal-driven biomass pyrolysis reactor, characterized in that, It includes a biomass pyrolysis reactor (1) and a circulating heat conduction component (2), wherein the biomass pyrolysis reactor (1) and the circulating heat conduction component (2) are connected by a heating pipe (3) and a heat return pipe (4) to form a heating circulation pipeline; The heating pipe (3) is equipped with a heating valve (5) for opening and closing the heating passage from the circulating heat conduction component (2) to the biomass pyrolysis reactor (1); the heat recovery pipe (4) is equipped with a heat recovery valve (6) for opening and closing the heat recovery passage from the biomass pyrolysis reactor (1) to the circulating heat conduction component (2). The circulating heat conduction assembly (2) includes a heating box (21), a heat exchange box (22) and a heating device (23). The heating box (21) and the heat exchange box (22) are connected by a first conduit (24) and a second conduit (25) to form a heating circulation pipeline. The heating device (23) is installed on the first conduit (24) and is used to heat the heat-conducting medium inside the first conduit (24); The first conduit (24) is also equipped with an air inlet (26), which is used to introduce inert gas into the first conduit (24); the inert gas is introduced into the heating box (21) in the first conduit (24). The second conduit (25) is used to connect the heat transfer medium from the heating box (21) to the heat exchange box (22), and a heating circulation valve (27) is provided on it. It also includes a control system (7) for switching between the hot circulation pipeline and the heating circulation pipeline by detecting the temperature of the hot circulation pipeline and the heating circulation pipeline and then controlling the opening and closing of each valve.

2. The solar thermal-driven biomass pyrolysis reactor according to claim 1, characterized in that: The biomass pyrolysis reactor (1) is connected to the heating pipe (3) and the regenerating pipe (4) via a heat exchange pipe (11); The heat exchange tube (11) is sleeved on the outside of the biomass pyrolysis reactor (1), and the heat exchange tube (11) exchanges heat with the biomass pyrolysis reactor (1) through the heat-conducting medium flowing inside it. The upper end of the heat exchange tube (11) is connected to the heating tube (3), and the lower end is connected to the heat recovery tube (4).

3. The solar thermal-driven biomass pyrolysis reactor according to claim 2, characterized in that: The biomass pyrolysis reactor (1) has multiple exhaust layers (12) distributed along the axial direction of the heat exchange tube (11); each exhaust layer (12) is connected to an exhaust port (13).

4. The solar thermal-driven biomass pyrolysis reactor according to claim 3, characterized in that: The exhaust port (13) is provided with a biomass pyrolysis catalyst, which is one of iron-based, zirconium-based, aluminum-based, or molecular sieve catalysts.

5. The solar thermal-driven biomass pyrolysis reactor according to claim 1, characterized in that: The heat-conducting medium is an organic heat-conducting oil or a molten salt.

6. A biomass pyrolysis reaction method, applicable to the apparatus described in any one of claims 1-5, characterized in that, Includes the following steps: Close the heating valve (5) and the regeneration valve (6), open the heating circulation valve (27), add the heat transfer medium into the heating box (21), and add biomass raw materials into the biomass pyrolysis reactor (1); The heating device (23) is turned on to heat the first conduit (24), and at the same time, inert gas is introduced into the first conduit (24) at a constant flow rate through the air inlet (26). The inert gas flows through the first conduit (24) to the heating box (21). The inert gas and the heat-conducting medium in the first conduit (24) form a mixed medium, which is heated and circulated in the heating circulation pipeline; Once the mixed medium in the heating circulation pipeline reaches the set temperature, open the heating valve (5) and the regeneration valve (6), and close the heating circulation valve (27); the mixed medium enters the heating circulation pipeline and exchanges heat with the biomass pyrolysis reactor (1); Wait for the biomass pyrolysis reactor (1) to pyrolyze the biomass raw material, and open the exhaust port (13) on the biomass pyrolysis reactor (1) to collect the pyrolysis gas and bio-oil; After pyrolysis, the heating equipment (23), heating valve (5) and regenerating valve (6) are turned off, and the heating circulation valve (27) is turned on. The mixed medium is cooled and circulated in the heating circulation pipeline. The biomass pyrolysis reactor (1) is cooled naturally. After the temperature of the mixed medium drops to room temperature, the air inlet (26) is closed.

7. The solar thermal-driven biomass pyrolysis reactor according to claim 6, characterized in that: The heat-conducting medium is organic heat-conducting oil; the inert gas is nitrogen; and the biomass raw material is poplar wood chips with a particle size of 80-100 mesh. The constant flow rate is 70 mL / min; the set temperature is 200-350℃.

8. The solar thermal-driven biomass pyrolysis reactor according to claim 6, characterized in that: The heat-conducting medium is a ternary molten salt with a mass fraction of 40% NaNO2, 7% NaNO3 and 53% KNO3, a melting point of 142-148℃ and a boiling point of 680℃; the inert gas is nitrogen; and the biomass raw material is poplar wood chips with a particle size of 80-100 mesh. The constant flow rate is 100 mL / min; the set temperature is 300-650℃.

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