A rotating reaction equipment and process suitable for high-temperature molten salt pyrolysis of biomass

Abstract

This invention discloses a rotary reaction apparatus and process suitable for high-temperature molten salt pyrolysis of biomass. The reaction apparatus includes a molten salt purging device, a molten salt inlet, a compartmentalized molten salt tank, an integrated stage, a nickel-based alloy mesh, a motor, a reaction apparatus shell, a gas detection system, a temperature detection and control system, baffles, and a heating layer. The apparatus is made of high-temperature and corrosion-resistant materials, making it suitable for high-temperature and highly corrosive environments. Based on the synergistic effect of the molten salt characteristics and the reaction apparatus, the utilization efficiency of the molten salt is effectively improved and the mass and heat transfer processes are enhanced through the significant thinning and renewal rate of the liquid film under hypergravity conditions. By adjusting the molten salt feed rate and the rotation speed of the rotary table, the pyrolysis process under different mass and heat transfer efficiencies can be explored. This invention can be extended to reaction systems such as liquid metals. The assembly of this invention is relatively efficient, with low investment, and it can explore the influence of mass and heat transfer during the pyrolysis process on the products, thereby obtaining relevant thermodynamic and kinetic parameters.

Description

Technical Field

[0001] This invention relates to the fields of high-temperature reaction engineering, biomass pyrolysis engineering, supergravity engineering technology, and mechanical engineering, specifically to a rotary reaction device and process suitable for high-temperature molten salt pyrolysis of biomass. Background Technology

[0002] In the process of producing syngas, H2, and other chemical feedstock gases from biomass through high-temperature pyrolysis, molten salts, due to their high heat capacity, excellent thermal conductivity, and easy permeability, can effectively produce high-grade target products. However, existing technologies still have corresponding technical problems, as follows: First, in the traditional high-temperature molten salt pyrolysis of biomass, a simple feeding method is generally adopted, where biomass is directly fed into the high-temperature molten salt reaction equipment. This method is prone to two major technical problems: First, it is difficult for biomass and molten salt to achieve sufficient contact and reaction, and only one-way natural permeation can occur. Moreover, this permeation is mostly in the form of bottom-up, which needs to overcome the effect of gravity to complete, directly resulting in very insufficient contact between the two and significantly low mass and heat transfer efficiency of the system. Second, in the traditional high-temperature pyrolysis of biomass, as the reaction proceeds, carbon deposits easily adhere to the molten salt surface, thereby reducing the pyrolysis efficiency.

[0003] Secondly, traditional high-gravity equipment, primarily based on rotating packed bed structures, is widely used in physical mass transfer processes such as distillation, absorption, and extraction in gas-liquid and liquid-liquid systems. However, it has not yet been applied to biomass pyrolysis. This type of equipment is unsuitable for pyrolysis conditions, both in principle and application: on the one hand, it requires extremely high rotational speeds to achieve material ejection and dispersion; on the other hand, the equipment itself exhibits significant pressure drop characteristics. The combined effect of high rotational speed and high pressure drop makes sealing extremely difficult, and the seals wear out rapidly in high-temperature, dusty environments, requiring frequent shutdowns for replacement. Furthermore, when processing high-viscosity or solid-containing feedstocks such as biomass, the packing layer is prone to clogging and scaling, severely restricting the continuous operation stability and long-term reliability of the equipment.

[0004] Third, traditional impeller-type reactors have significant limitations when processing high-temperature molten salt and biomass materials. Due to the high viscosity and poor flowability of molten salt, conventional impellers struggle to create uniform and effective agitation throughout the reactor, hindering mass and heat transfer. Even if the impeller blades can agitate the material surface and renew the molten salt layer in contact with the wood, they still lack a substantial promoting effect on the pyrolysis process inside the biomass particles, preventing the molten salt and material from achieving full and efficient contact and heat transfer. Furthermore, during high-speed rotation, the impeller blades are prone to hard collisions with irregularly shaped biomass particles with large density differences. This not only causes agitator shaft polarization and affects the stable operation of the equipment, but in severe cases, it can also directly damage the impeller blades, affecting the continuous and stable operation of the equipment.

[0005] In summary, there is an urgent need in the existing technology for a high-efficiency pyrolysis device that can achieve comprehensive and deep contact between biomass and molten salt, significantly improve the mass and heat transfer rate, and avoid risks such as equipment blockage, seal failure and mechanical damage. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by providing a rotary reaction device and process suitable for high-temperature molten salt pyrolysis of biomass, thereby enhancing mass and heat transfer, reducing molten salt loss, and enabling controllable monitoring of the reaction process. The device uses high-temperature and corrosion-resistant materials and overcomes the problems of high salt content, low unidirectional mass and heat transfer efficiency in traditional molten salt pyrolysis through the synergistic effect of the high-gravity rotating stage and the molten salt inlet. It can efficiently and flexibly explore the reaction mechanism and process parameters of biomass pyrolysis.

[0007] This invention is achieved through the following technical solution: In a first aspect, the present invention provides a rotary reaction apparatus suitable for high-temperature molten salt pyrolysis of biomass. The reaction apparatus includes a molten salt purging device 19, a molten salt inlet 8, a compartmentalized molten salt tank 7, a molten salt pump 1, an integrated platform 6, a nickel-based alloy mesh 23, a motor 20, a reaction apparatus cover, a reaction apparatus shell, a gas detection device, a liquid phase detection device, a temperature detection and control system, a condensation device, a baffle 5, and a heating layer. The reaction apparatus has a reaction apparatus cover and a reaction apparatus shell, which are connected by a flange 25. The motor 20 is located above the reaction apparatus cover and is integrally connected to a rotating shaft via a coupling. The rotating shaft extends downward into the interior of the rotary reaction apparatus and is connected to the integrated platform. The platform 6 is fixedly connected as an integral unit. The integrated platform 6 is used to carry biomass materials and has baffles 5 on its edge. The baffles 5 are covered with nickel-based alloy mesh 23 and supplemented with pressure ring counterweights 23 to fix the materials. The compartmentalized molten salt tank 7 is set below the reaction equipment and is divided into a left side chamber and a right side chamber. The left side chamber is connected to the molten salt inlet 22 on the side of the reaction equipment cover through a molten salt pipe and a molten salt pump 1. The molten salt inlet 22 is connected to the molten salt guide port 8 at the lower end of the reaction equipment cover. The molten salt outlet is set at the bottom of the reaction equipment shell and is connected to the right side chamber of the compartmentalized molten salt tank 7 through a molten salt pipe. The molten salt purging device (19) is equipped with a gas preheater 18 and has a valve inlet.

[0008] Furthermore, the reaction equipment is made of corrosion-resistant and high-temperature resistant alloy material. The outer shell of the reaction equipment and the outer shell of the compartmentalized molten salt tank 7 are covered with a heating layer, and a heating jacket is provided on the heating layer. The heating jacket is electrically connected to the temperature detection and control system 10, and the temperature detection and control system is used to monitor and control the temperature of the heating jacket in real time.

[0009] Furthermore, the reaction equipment cover is provided with a reaction cover air inlet 24 and a reaction cover air outlet (26). The reaction cover air inlet 24 is connected to a nitrogen cylinder 2 and a carbon dioxide cylinder 3. The compartmentalized molten salt tank 7 is provided with a compartmentalized tank air inlet. The compartmentalized tank air inlet is connected to an oxygen cylinder 4. Each cylinder's gas pipe is equipped with a flow meter and a regulating valve.

[0010] Furthermore, the gas outlet 26 on the cover of the reaction equipment is connected in sequence to the condenser 17, the gas washing device 16, the wet gas flow meter 15, and the gas collection bag 14 via a rubber hose; the gas phase in the gas collection bag 14 is analyzed using a gas detection device; the liquid phase outlet of the condenser 17 is connected to the liquid phase receiving flask 11 and analyzed by the liquid phase detection device.

[0011] Furthermore, the gas detection device is a gas chromatograph, and the liquid detection device is a gas chromatography-mass spectrometry (GC-MS) instrument.

[0012] Furthermore, a stuffing box seal is used between the reaction equipment and the motor.

[0013] Furthermore, the bottom of the rotating shaft and the rotating shaft housing are provided with an opening structure, which allows a small amount of molten salt to enter the opening structure and form a continuous and stable liquid film between the relatively moving surfaces by utilizing the fluid properties of the molten salt.

[0014] Furthermore, the molten salt purging device 19 is used to purge key parts inside the rotary reaction equipment with high-pressure gas after the reaction is completed to thoroughly remove residual molten salt.

[0015] Furthermore, the key internal components include the gap between the rotating shaft and the outer casing, and the molten salt inlet 8.

[0016] Secondly, the present invention provides a process based on the aforementioned rotary reaction equipment suitable for high-temperature molten salt pyrolysis of biomass, comprising the following steps: Complete the overall assembly of the reaction equipment and the pre-filling of materials, connect the pipelines and electrical lines, and ensure the airtightness and connection reliability of the rotary reaction equipment; Open nitrogen cylinder 2 and continuously introduce nitrogen into the reaction equipment; Turn on the condensation device 17, and simultaneously start the heating jacket to open the heating molten salt tank and related pipes and jacket; After the air inside the equipment has been completely replaced and the system temperature has risen to the set process temperature, close nitrogen cylinder 2 and start molten salt pump 1. The drive motor 2 is started at low speed. The material is stably fixed on the integrated platform under the combined action of centrifugal force, pressure of the pressure ring counterweight 21, and integrated platform 6. The platform is accelerated by rotating the shaft. The gaseous and liquid products generated during the reaction are analyzed in real time by the gas phase detection device and the liquid phase detection device, respectively. After the reaction is complete, continue heating and turn on the molten salt purging device 19 to purge the internal device; after purging, wait for the temperature inside the equipment to cool down and then turn off the condenser device 17.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. Traditional processes rely on large amounts of molten salt to submerge biomass, resulting in high salt content, difficulty in separating molten salt from carbon deposits, and high recycling costs. This invention proposes an optimized scheme based on hypergravity liquid film enhancement and molten salt recycling. First, compared with traditional biomass pyrolysis equipment, this equipment utilizes hypergravity to significantly thin the liquid film, greatly reducing the intrinsic liquid holdup of the reaction system. This reduction in liquid holdup effectively shortens the thermal response time during start-up and shutdown, thereby reducing overall energy consumption. Furthermore, due to the thinner liquid film, the amount of molten salt adhering to the inner wall of the equipment is significantly reduced, effectively alleviating the problem of molten salt corrosion at high temperatures and improving the operational stability and service life of the equipment. On the other hand, this reaction equipment utilizes the liquid film formed by molten salt under centrifugal force to peel off and remove the carbon deposits generated during the reaction from the biomass surface, thereby significantly improving mass and heat transfer efficiency. The removed carbon deposits enter the compartmented molten salt tank with the molten salt, where efficient separation is achieved through settling by baffles and oxygen-assisted combustion, achieving the recycling of molten salt. This process reduces the overall salt content of the process by combining "improving individual efficiency" and "promoting circulation," thereby reducing net loss of molten salt and subsequent salt slag treatment costs.

[0018] 2. Enhanced mass and heat transfer efficiency, improving the grade of pyrolysis products. This invention utilizes the centrifugal force generated by the rotating platform under hypergravity. On one hand, it stretches the molten salt into a uniform thin liquid film, achieving efficient coverage. Hypergravity also enhances the penetration ability of the molten salt, greatly improving the mass and heat transfer efficiency per unit of molten salt. On the other hand, it drives the molten salt, quantitatively added from the molten salt inlet, to move radially from the center to the edge of the platform. With the constraint of the irregular structure of the baffles and wooden blocks, vortices and splashes are formed, allowing the molten salt to quickly and uniformly envelop and permeate the biomass material from all directions (rather than the traditional unidirectional bottom-up movement against gravity). This dynamic and forced contact method greatly increases the contact area and renewal frequency between the two phases. Furthermore, the molten salt removes the carbon deposits generated during the reaction, improving subsequent mass and heat transfer efficiency. This overcomes the limitations of traditional static immersion or unidirectional permeation in mass and heat transfer, as well as the impact of carbon deposits on pyrolysis efficiency.

[0019] 3. Fully utilizing the physical properties of molten salt, a targeted structural design is implemented for the rotating shaft and the molten salt. In traditional high-temperature rotating equipment, direct friction between rotating components, eccentric vibration caused by high-temperature thermal deformation, and rapid wear of seals are long-standing industry pain points. This invention features an opening structure at the bottom of the rotating shaft and the bottom of the guide port. During operation, a small amount of molten salt enters the gap under hydraulic pressure, forming a continuous and stable liquid film between the relatively moving surfaces using the fluid properties of the molten salt. This liquid film acts as a support and lubrication mechanism, similar to a sliding bearing, effectively preventing direct friction between metal parts and significantly suppressing eccentric vibration. This fundamentally simplifies the sealing structure of high-temperature rotating components, ensuring long-term stable operation of the equipment.

[0020] 4. Unlike traditional impeller-type reaction equipment, this invention uses a platform to fix the material, avoiding hard collisions and significantly improving the operational stability of the equipment. When processing high-viscosity molten salts and irregularly shaped biomass particles with large density differences, traditional impellers are prone to hard collisions with the material, leading to agitation shaft polarization and impeller damage, severely affecting the continuous and stable operation of the equipment. This invention achieves reliable fixation of the reactants through a combination of edge baffles on the platform, a nickel-based alloy mesh covering it, and corrosion-resistant counterweights. The material is stabilized on the platform under the synergistic effect of centrifugal force and mechanical fixation, with no direct impact between rotating parts and the material. This ensures the stability of the reaction process and significantly reduces the equipment failure rate.

[0021] 5. High adaptability, wide range of applications and expandability. The entire device is made of high-temperature and corrosion-resistant materials (such as the rotating shaft housing, which is made of corrosion-resistant and high-temperature resistant metal), making it stable and suitable for high-temperature and highly corrosive molten salt pyrolysis environments. At the same time, the design concept of this device can be extended to other fluid reaction systems such as liquid metals, not just limited to high-temperature molten salt pyrolysis of biomass processes, making it more adaptable and applicable to a wider range of scenarios.

[0022] 6. The atmosphere is adjustable at any time, allowing for targeted control of the reaction and optimization of target products. The reaction equipment cover connects to nitrogen and carbon dioxide cylinders, etc. Nitrogen can be used to purge the air from the equipment before the experiment to prevent air from interfering with the pyrolysis reaction; carbon dioxide can be used to adjust the atmosphere inside the equipment during the reaction, directionally promoting the generation of target products such as syngas, further improving the product quality. Compared with traditional processes that cannot flexibly adjust the reaction atmosphere, this has a stronger product control capability. Attached Figure Description

[0023] Figure 1 This is a structural diagram of a rotary reaction device for high-temperature molten salt pyrolysis of biomass, constructed according to the present invention. Figure 2This is a comparison diagram of the rotary reaction equipment for high-temperature molten salt pyrolysis of biomass constructed according to the present invention, in both operating and shutdown states. A is the shutdown state diagram, and B is the operating state diagram. Figure 3 These are comparison images of the molten state and the solidified state after molten salt pyrolysis. Image a is the molten state image, and image b is the solidified state image. Reference numerals: 1-Molten salt pump, 2-Nitrogen cylinder, 3-Carbon dioxide cylinder, 4-Oxygen cylinder, 5-Baffle, 6-Integrated stage, 7-Compartmental molten salt tank, 8-Molten salt inlet, 9-Heating jacket, 10-Temperature detection and control system, 11-Liquid phase receiving flask, 12-Gas chromatograph-mass spectrometer, 13-Gas chromatograph, 14-Gas collection bag, 15-Wet gas flow meter, 16-Gas washing device, 17-Condensing device, 18-Preheater, 19-Molten salt purging device, 20-Motor, 21-Pressure ring load, 22-Molten salt inlet, 23-Nickel-based alloy mesh, 24-Reaction equipment cover inlet, 25-Flange, 26-Reaction equipment cover outlet, 27-Coupling. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] It should be noted that, unless otherwise specified, the features in the following embodiments and implementation methods can be combined with each other.

[0026] Unless otherwise specified, all raw materials used in this invention are obtained through commercial purchases; all equipment involved in this invention are conventional equipment in the relevant technical field or commercially available standard equipment.

[0027] This invention utilizes high-temperature molten salt as a heat carrier and reaction medium, and combines the properties of molten salt to perform pyrolysis treatment on biomass within the reaction equipment.

[0028] In a first aspect, the present invention provides a rotary reaction device suitable for high-temperature molten salt pyrolysis of biomass, the rotary reaction device comprising a molten salt purging device 19, a molten salt guide port 8, a compartmentalized molten salt tank 7, a molten salt pump 1, an integrated platform 6, a nickel-based alloy mesh 23, a motor 20, a reaction device cover, a reaction device shell, a gas detection device, a liquid phase detection device, a temperature detection and control system 10, a condensation device 17, a baffle 5, and a heating layer; In the rotary reaction device provided by the present invention, the reaction device is provided with a reaction device cover and a reaction device shell, which are sealed and connected by a flange 25. The reaction device cover is provided with a reaction cover inlet 24 and a reaction cover outlet 26, and the lower end of the reaction device cover is provided with a molten salt guide port 8. The reaction device and the motor 20 are sealed by a stuffing box to achieve a sealing effect. The motor 20 is integrally connected to the rotating shaft through an expansion coupling. The lower end of the rotating shaft is integrally fixedly connected to an integrated platform 6 and extends into the interior of the rotary reaction device. The edge of the integrated platform 6 is provided with a baffle 5. The baffle 5 is covered with a nickel-based alloy mesh 23 and supplemented with a corrosion-resistant pressure ring counterweight 23 to fix the material. The nickel-based alloy mesh 23 has a certain thickness to provide a stable adhesion interface for the liquid film above the material, thereby avoiding the weakening of the upper layer mass transfer and heat transfer efficiency due to the pressure ring counterweight.

[0029] The reaction equipment is made of corrosion-resistant and high-temperature resistant alloy material. The outer shell of the reaction equipment and the outer shell of the compartmentalized molten salt tank are covered with a heating layer, and a heating jacket is provided on the heating layer. The temperature detection controller is used to monitor and control the temperature of the heating jacket in real time.

[0030] The compartmentalized molten salt tank 7 is arranged in a low position and is divided into a left side chamber and a right side chamber. Molten salt is connected from the left side chamber to the molten salt inlet 22 on the side of the reaction equipment cover through a molten salt pipeline and a molten salt pump 1. Then, it enters the integrated platform 6 through the molten salt guide port 8 at the lower end of the reaction equipment cover. After the reaction, the molten salt flows back to the right side chamber of the compartmentalized molten salt tank 7 through the molten salt outlet at the bottom of the reaction equipment shell and a molten salt pipeline. The molten salt guide port has a porous structure and is located at the lower end of the reaction equipment cover. It is connected to the molten salt inlet 22 and is used to uniformly guide the molten salt to the top of the platform.

[0031] Molten salt is transported through molten salt pipelines, all of which are equipped with insulation jackets.

[0032] Nitrogen cylinder 2 and carbon dioxide cylinder 3 are respectively connected to the air inlet 24 of the reaction equipment cover, and oxygen cylinder 4 is connected to the air inlet of the compartment of the compartmentalized molten salt tank 7; each cylinder is equipped with a flow meter and a regulating valve on its gas pipe. Nitrogen cylinder 2 is used to purge the air in the reaction equipment before operation; carbon dioxide cylinder 3 is used to regulate the atmosphere in the reaction equipment during operation to obtain a higher quality syngas product; oxygen cylinder 4 is used to supply oxygen to the compartmentalized molten salt tank (7) for carbon removal.

[0033] The gas outlet 26 on the cover of the reaction equipment is connected in sequence to the condenser 17, the gas washing device 16, the wet gas flow meter 15, and the gas collection bag 14 via a rubber hose; the gas phase in the gas collection bag 14 is analyzed by a gas detection device; the liquid phase outlet of the condenser 17 is connected to the liquid phase receiving flask 11 and analyzed by a liquid phase detection device; wherein, the gas detection device is specifically a gas chromatograph 13, and the liquid phase detection device is specifically a gas chromatography-mass spectrometry system 12.

[0034] The condensation device is used to recover the liquid phase component from the pyrolysis products.

[0035] The molten salt purging device 19 is equipped with a gas preheater 18 and a valve inlet. The inlet can directly blow to key parts such as the gap between the rotating shaft and the outer shell and the molten salt guide port 8. The gas preheater 18 is used to prevent the molten salt from solidifying when it encounters cold gas during the purging process.

[0036] The temperature detection and control system 10 is used to detect and control the temperature of the heating jacket in real time; it is electrically connected to the outside of the reaction equipment shell and the heating layer outside the compartmentalized molten salt tank, thereby realizing the efficient and coordinated operation of the whole equipment.

[0037] The molten salt pump is equipped with a jacket for heat preservation and nitrogen sealing. After shutdown, it is necessary to vent the gas to prevent the molten salt from solidifying and expanding, which could damage the molten salt pump.

[0038] Furthermore, the bottom of the rotating shaft and its housing is provided with an opening structure. During operation, under the hydraulic pressure of the molten salt itself, a small amount of molten salt can enter the gap of this opening and form a continuous and stable liquid film between the relatively moving surfaces by utilizing the fluid properties of the molten salt. This liquid film can play a supporting and lubricating role similar to that of a sliding bearing, effectively avoiding direct friction and scratching between the rotating shaft and the housing, thereby preventing damage to the rotating shaft and ensuring long-term stable operation of the equipment.

[0039] Furthermore, the purging device is used to purge key internal parts of the device (such as the gap between the rotating shaft and the outer shell, the molten salt inlet, etc.) with high-pressure gas after the reaction is completed, in order to thoroughly remove residual molten salt. Since molten salt expands in volume after cooling and solidifying, if it remains in a narrow gap, the expansion stress may compress or even damage the rotating shaft, causing the equipment to jam or be damaged, thus affecting its next use. Timely purging can effectively avoid these risks and ensure the long-term stable operation of the equipment.

[0040] This invention utilizes high-temperature molten salt as a heat carrier and reaction medium, and combines the properties of molten salt to perform pyrolysis treatment on biomass within the reaction equipment.

[0041] This invention differs from traditional centrifugal rotating devices, which are mainly used for physical mass transfer processes such as distillation, absorption, and extraction between gas-liquid, liquid-liquid, or solid-liquid phases. The rotating reaction device provided by this invention is specifically designed for biomass pyrolysis chemical reactions in a high-temperature molten salt environment. By arranging biomass raw materials on an integrated platform 6 and introducing the combination of molten salt and centrifugal force, a highly efficient heat transfer and reaction system is formed, realizing the innovative application of molten salt pyrolysis technology in this type of centrifugal device.

[0042] This invention utilizes the fluid properties of molten salt at high temperatures to form a continuous molten salt lubricating film inside the rotating shaft cavity and between the integrated stage 6 and the molten salt guide port 8. This molten salt layer plays a supporting and lubricating role similar to a sliding bearing during rotation, effectively reducing direct friction between metal parts and significantly suppressing eccentric vibrations caused by high-temperature thermal deformation or uneven load.

[0043] Furthermore, regarding the risk of equipment damage due to phase change expansion of molten salt after cooling, the mechanism is as follows: the outer molten salt cools and solidifies first, forming an outer shell; the inner molten salt expands in volume during subsequent solidification, squeezing the outer shell outward and continuously bursting and expanding, forming the aforementioned volume change pattern. This equipment is equipped with a cavity-structured molten salt purging device 19 inside the rotating shaft shell. After the reaction is completed, high-temperature and high-pressure gas is introduced into the space between the rotating shaft and the outer shell, as well as into the molten salt inlet 8, through the molten salt purging device 10, to forcibly blow away the residual molten salt from the critical mating surfaces, preventing the rotating shaft from seizing or the inlet from becoming blocked due to volume expansion after the molten salt has cooled, thus ensuring the normal operation of the equipment during the next startup.

[0044] The compartmentalized molten salt tank is positioned low, and molten salt is driven into the reaction equipment by a molten salt pump. The tank is divided into two chambers: the right chamber receives the reacted molten salt and contains baffles and gas inlets / outlets. The baffles extend the residence time of the molten salt within the chamber to promote the separation of carbonaceous components; the gas inlet introduces oxygen to burn the separated carbon, thereby achieving decoking and improving the recycling rate of the molten salt.

[0045] By using supergravity to stretch the liquid film to accelerate the renewal of molten salt in the reaction equipment, the liquid holdup in the equipment is significantly reduced. This not only improves the pyrolysis efficiency, but also reduces molten salt corrosion and shortens the thermal response time, thereby optimizing the product structure and enhancing the safety and sustainability of the device.

[0046] Secondly, the present invention provides a process for a rotary reaction apparatus suitable for high-temperature molten salt pyrolysis of biomass, comprising the following steps: Complete the overall assembly of the reaction equipment and the pre-filling of materials, connect all pipelines and electrical lines, and ensure the airtightness and reliability of the equipment.

[0047] Open nitrogen cylinder 2 and continuously introduce nitrogen into the reaction equipment through inlet 24 to fully replace and purge the air inside the equipment, forming an inert protective atmosphere to facilitate the subsequent pyrolysis reaction.

[0048] Turn on the cooling water circulation of the condensing device 17 to ensure the stable operation of the condensing system; simultaneously start the heating jacket to open the heating molten salt tank and related pipes and jacket.

[0049] After the air inside the equipment is completely replaced and the system temperature rises to the set process temperature, close the nitrogen cylinder 2 and start the molten salt pump 1 to begin operation.

[0050] The drive motor 2 is started at low speed. Under the combined action of centrifugal force, the pressure of the pressure ring counterweight 21, and the integrated platform, the material is stably fixed on the integrated platform 6. The integrated platform 6 is accelerated by the rotating shaft, which allows the molten salt to quickly coat the surface of the biomass and achieve full-dimensional penetration, significantly enhancing the heat and mass transfer efficiency of the system. During the reaction, the generated gaseous and liquid products are analyzed in real time by gas phase detection devices and liquid phase detection devices, respectively, to optimize and determine various process parameters.

[0051] After the reaction is complete, continue heating and turn on the molten salt purging device 19 to purge the internal devices such as the rotating shaft and the integrated stage 6 to reduce molten salt residue and prevent damage to the equipment. After purging, wait for the temperature inside the equipment to cool down and then turn off the circulating condensate water. The process ends here.

[0052] Example 1: This embodiment uses a ternary mixed molten salt of potassium carbonate, sodium carbonate, and lithium carbonate, N2 atmosphere, and birch wood block biomass as raw materials; and is based on small laboratory equipment.

[0053] This invention constructs a high-gravity reactor suitable for high-temperature molten salt pyrolysis of biomass. The method of use is as follows: Birch wood is selected as the biomass raw material. After cutting, 20g of birch wood blocks with a particle size of 1cm are taken and laid flat on the integrated platform 6. A nickel-based alloy mesh 23 is covered, and a corrosion-resistant pressure ring 21 is placed for fixation. A ternary carbonate (potassium carbonate-sodium carbonate-lithium carbonate, molar ratio 3:3:4) is selected as the heat transfer medium.

[0054] First, assemble the relevant equipment and connect the pipelines and wires; Open nitrogen cylinder 2 and continuously introduce nitrogen into the reaction equipment through inlet 24 at a flow rate of 0.2 L / min for 10 minutes to purge the air from the equipment. Turn on the cooling water circulation of the condenser 17; pre-melt the molten salt in the compartmentalized molten salt tank 7 and heat it to 550°C, then start the heating jacket 9 and the temperature detection and control terminal 10 to stabilize the internal temperature of the reaction equipment at 550°C. Turn on the cooling water circulation of the condenser 17; Start the molten salt pump 1 to deliver molten salt at 550℃ to the molten salt inlet 22 at a flow rate of 0.2 L / min. The molten salt drips evenly onto the center of the stage 6 through the molten salt guide port 8. At the same time, start the motor 2) and set the rotation speed of the stage 6 to 50 rpm, 100 rpm, 200 rpm and 400 rpm respectively, and stabilize the reaction for 20 minutes at each speed. During the reaction, the generated pyrolysis gas is discharged through outlet 26, passes sequentially through condenser 17 and gas washing device 18, and its gas composition is analyzed online by gas chromatograph 13, while the gas volume is measured by wet gas flow meter 15. The liquid phase product is collected in liquid phase receiving flask 11 and then analyzed by gas chromatography-mass spectrometry 12. The compartmentalized molten salt tank 7 is vented with oxygen through an oxygen inlet to achieve timely removal of carbon from the molten salt.

[0055] A rotation speed of 200 rpm was selected, and the flow rate of molten salt pump 1 was set to 0.5 L / min, 1 L / min, 1.5 L / min, 2 L / min, and 2.5 L / min, respectively. The above reaction, collection, and analysis steps were repeated.

[0056] Analysis results show that under conditions of 550℃, 200 rpm, and 0.5 L / min, the pyrolysis gas yield reached 49.3%, with H2 accounting for 28.4% and CO accounting for 21.7%. In contrast, the gas yield of traditional direct pyrolysis of biomass with molten salt at 550℃ is typically around 35%, with H2 and CO accounting for less than 15% and 20% respectively, and syngas accounting for less than 40% of the total gas. This improvement is mainly attributed to the thinning of the liquid film due to hypergravity, which promotes rapid molten salt renewal, optimizes the mass and heat transfer processes, and effectively removes the carbon deposits on the surface of biomass during pyrolysis using molten salt.

[0057] After the reaction is complete, maintain heating and turn on the preheater 18 and molten salt gas purging device 19 to purge preheated high-pressure nitrogen gas into key areas such as between the rotating shaft and the outer shell, and the molten salt inlet 8, blowing the residual molten salt into the right chamber of the compartmentalized molten salt tank 7. After the reaction equipment cools to room temperature, turn off all power and cooling water, and remove the biochar sample for subsequent analysis.

[0058] Example 2: This embodiment uses a ternary mixed molten salt of potassium carbonate, sodium carbonate, and lithium carbonate, N2 atmosphere, and poplar wood block biomass as raw materials, based on large-scale industrial equipment.

[0059] The industrial-grade equipment was configured and raw materials were prepared. An industrial-grade potassium carbonate-sodium carbonate-lithium carbonate ternary mixed molten salt (molar ratio 3:3:4) was selected as the heat carrier, with a total loading of 500 kg, stored in a compartmentalized molten salt tank. The biomass raw material consisted of crushed poplar wood blocks with a particle size of 5-10 cm, evenly spread on an integrated platform 6. The platform 6 had a diameter of 2 meters and a perimeter baffle 5. A high-temperature resistant nickel-based alloy mesh 23 was automatically placed over the material and reliably secured with a corrosion-resistant pressure ring load 21 to ensure material stability under high-speed rotation.

[0060] Initiate the industrial operation process. First, open nitrogen cylinder 2 and purge nitrogen gas through inlet 24 at a speed of 2m. 3 Nitrogen gas is continuously introduced into the entire reaction equipment system (shell) at a rate of / min, for a volume of approximately 5m³. 3 The reaction space is thoroughly purged to remove air and establish an inert protective atmosphere. Simultaneously, the heating systems of all molten salt pipes' insulation jackets, the heating jacket 9 of the reaction equipment body, and the compartmentalized molten salt tank 7 are activated. The molten salt in the tank is heated and kept constant at 550°C via the temperature detection and control system 10, thus stabilizing the internal temperature of the reaction equipment at 550±5°C. The industrial-grade cooling circulating water system of the condenser 17 is then activated.

[0061] Once the system temperature and atmosphere reach the set values, the molten salt pump 1 (equipped with jacket insulation and nitrogen sealing) is started, delivering 550°C liquid molten salt at a flow rate of 1500 L / h from the left chamber of the compartmentalized molten salt tank 7 to the molten salt inlet 22 on the side of the reaction equipment cover. The molten salt is uniformly and continuously delivered to the central area of ​​the rotating platform 6 through a specially designed molten salt guide port 8. Simultaneously, the high-power drive motor 20 is started, driving the rotating shaft through an expansion coupling to increase and stabilize the rotation speed of the platform 6 at 350 rpm. Under the influence of the hypergravity field, the molten salt rapidly spreads from the center to the edge, forming a uniform and rapidly renewing thin liquid film, achieving full-dimensional, forced coating and penetration of the poplar wood block, instantly initiating a highly efficient pyrolysis reaction. During this process, a small amount of molten salt seeps into the gap between the rotating shaft and the bottom of the outer shell, forming a continuous lubricating film, ensuring the stable operation of the rotating components at high temperatures without direct friction or vibration.

[0062] The crude pyrolysis gas mixture produced by the reaction is discharged through the gas outlet 26 on the cover of the reaction equipment, and then enters the industrial-grade condenser 17 to separate liquid products such as bio-oil, which are collected in a large storage tank. The non-condensable gases are purified by the gas washing device 16. Part of the gas is continuously monitored by an online gas chromatograph 13 for its composition (H2, CO, CH4, CO2, etc.), while the other part is measured by a wet gas flow meter 15 and can be collected or utilized as fuel gas or feedstock gas for subsequent synthesis stages.

[0063] During the reaction, the molten salt, carrying the carbon deposits produced by pyrolysis, is thrown off the edge of the platform 6 under centrifugal force. After being collected at the molten salt outlet, it flows back to the right chamber of the compartmentalized molten salt tank 7 by gravity. A baffle 5 is installed in the right chamber to prolong the residence time of the molten salt and promote the sedimentation and separation of carbonaceous components. Simultaneously, industrial oxygen supplied by oxygen cylinder 4 is introduced into the bottom of the right chamber through the air inlet, causing the separated carbon deposits to undergo gentle combustion below the molten salt surface, achieving online decoking and decarbonization regeneration of the molten salt. The regenerated molten salt overflows back to the left chamber and is then pumped back into the reaction equipment by molten salt pump 1, forming a continuous and efficient molten salt recycling system, significantly reducing net molten salt loss and processing costs.

[0064] After the biomass on platform 6 has completely reacted, stop molten salt pump 1 and vent the molten salt from the pump body. Then, maintain heating, turn on preheater 18 and molten salt gas purging device 19, and purge preheated high-pressure nitrogen gas into key areas such as the gap between the rotating shaft and the outer casing, and the molten salt inlet 8. Thoroughly purge residual molten salt into the compartmentalized molten salt tank 7 to prevent the rotating shaft from seizing or key channels from becoming blocked due to the solidification and expansion of the molten salt after cooling. After purging, stop motor 20 and shut down the heating system according to the procedure; the system then enters standby or cooling mode.

[0065] In this embodiment, the ternary carbonate can be replaced with other single or multi-component molten salts (such as nitrates, chlorides, phosphates, sulfates, etc.). Only the temperature needs to be adjusted to correspond to the various types of salts, and the temperature and flow rate of the condensate need to be changed.

[0066] It should be noted that in other embodiments of the present invention, only the components, proportions, temperature control, flow rate control, etc., described in this example are different. Other different corresponding embodiments can be obtained by making specific selections, so they are not listed here one by one.

[0067] The above embodiments are provided to illustrate specific implementation methods of the present invention. Their purpose is to enable those skilled in the art to understand the invention and use it accordingly. The scope of protection of the present invention is not limited to the above embodiments. Therefore, any equivalent changes or modifications made based on the design concept given in the present invention are within the scope of protection of the present invention.

Claims

1. A rotary reaction apparatus suitable for high-temperature molten salt pyrolysis of biomass, characterized in that, The reaction equipment includes a molten salt purging device (19), a molten salt inlet (8), a compartmentalized molten salt tank (7), a molten salt pump (1), an integrated platform (6), a nickel-based alloy mesh (23), a motor (20), a reaction equipment cover, a reaction equipment shell, a gas detection device, a liquid phase detection device, a temperature detection and control system, a condensation device, a baffle (5), and a heating layer; wherein, the reaction equipment is provided with a reaction equipment cover and a reaction equipment shell, which are connected by a flange (25); the motor (20) is located above the reaction equipment cover and is integrally connected to a rotating shaft through a coupling, the rotating shaft extends downward into the interior of the rotary reaction equipment and is integrally fixedly connected to the integrated platform (6), the integrated platform The platform (6) is used to carry biomass materials, and its edge is provided with baffles (5); the baffles (5) are covered with nickel-based alloy mesh (23) and supplemented with pressure ring counterweights (23) to fix the materials; the compartmentalized molten salt tank (7) is set below the reaction equipment and is divided into a left side chamber and a right side chamber; the left side chamber is connected to the molten salt inlet (22) on the side of the reaction equipment cover through a molten salt pipe and a molten salt pump (1), the molten salt inlet (22) is connected to the molten salt guide port (8) at the lower end of the reaction equipment cover, and the molten salt outlet is set at the bottom of the reaction equipment shell and is connected to the right side chamber of the compartmentalized molten salt tank (7) through a molten salt pipe; the molten salt purging device (19) is equipped with a gas preheater (18) and has a valve inlet.

2. The rotary reaction apparatus according to claim 1, characterized in that, The reaction equipment is made of corrosion-resistant and high-temperature resistant alloy material. The outer shell of the reaction equipment and the outer shell of the compartmentalized molten salt tank (7) are covered with a heating layer, and a heating jacket is provided on the heating layer. The heating jacket is electrically connected to the temperature detection and control system (10), and the temperature detection and control system is used to monitor and control the temperature of the heating jacket in real time.

3. The rotary reaction apparatus according to claim 1, characterized in that, The reaction equipment cover is provided with a reaction cover inlet (24) and a reaction cover outlet (26). The reaction cover inlet (24) is connected to a nitrogen cylinder (2) and a carbon dioxide cylinder (3). The compartmentalized molten salt tank (7) is provided with a compartmentalized tank inlet. The compartmentalized tank inlet is connected to an oxygen cylinder (4). The gas pipes of the cylinders are equipped with flow meters and regulating valves.

4. The rotary reaction apparatus according to claim 1, wherein The gas outlet (26) on the cover of the reaction equipment is connected in sequence to the condenser (17), the gas washing device (16), the wet gas flow meter (15) and the gas collection bag (14) by a rubber hose; the gas phase in the gas collection bag (14) is analyzed by a gas detection device; the liquid phase outlet of the condenser (17) is connected to the liquid phase receiving flask (11) and analyzed by the liquid phase detection device.

5. The rotary reaction apparatus according to claim 4, wherein The gas detection device is a gas chromatograph, and the liquid detection device is a gas chromatography-mass spectrometry (GC-MS) instrument.

6. The rotary reaction apparatus according to claim 1, characterized in that, The reaction equipment and the motor are sealed with a stuffing box.

7. The rotary reaction apparatus according to claim 1, wherein An opening structure is provided at the bottom of the rotating shaft and the rotating shaft housing, allowing a small amount of molten salt to enter the opening structure and form a continuous and stable liquid film between the relatively moving surfaces by utilizing the fluid properties of the molten salt.

8. The rotary reaction apparatus according to claim 1, characterized by The molten salt purging device (19) is used to purge key parts inside the rotary reaction equipment with high-pressure gas after the reaction is completed to thoroughly remove residual molten salt.

9. The rotary reaction apparatus according to claim 8, characterized by The key internal components include the gap between the rotating shaft and the outer shell, and the molten salt inlet (8).

10. A process based on the rotary reaction equipment for high-temperature molten salt pyrolysis of biomass as described in claims 1-9, characterized in that, Includes the following steps: Complete the overall assembly of the reaction equipment and the pre-filling of materials, connect the pipelines and electrical lines, and ensure the airtightness and connection reliability of the rotary reaction equipment; Open the nitrogen cylinder (2) and continuously introduce nitrogen into the reaction equipment; Turn on the condensation device (17), and simultaneously start the heating jacket to open the heating molten salt tank and related pipes and jacket; After the air inside the equipment is completely replaced and the system temperature rises to the set process temperature, close the nitrogen cylinder (2) and turn on the molten salt pump (1). Start the drive motor (2) and adopt a low-speed start mode. The material is stably fixed on the integrated platform (6) under the combined action of centrifugal force, pressure of the pressure ring counterweight (21) and integrated platform (6). The platform is accelerated by rotating the shaft. The gas phase and liquid phase products generated during the reaction are analyzed in real time by the gas phase detection device and the liquid phase detection device, respectively. After the reaction is complete, continue heating and turn on the molten salt purging device (19) to purge the internal device; after the purging is completed, wait for the temperature inside the equipment to cool down and then turn off the condenser (17).

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