Shockwave cyclone device and method for biomass flash pyrolysis

Abstract

This invention discloses a shock wave vortex device and method for biomass flash pyrolysis. The device includes at least: a shock wave preheating section, which is a furnace tube structure with constricted ends. The furnace tube includes a shell and a rotating shaft with the same shape as the shell, which is disposed inside the shell. The circumferential gap between the rotating shaft and the shell forms a gas channel. In the gas channel, at corresponding positions along the gas flow direction in the straight section of the furnace tube, there are sequentially arranged: a first stator for initial acceleration of process gas, a rotor for accelerating process gas to supersonic speed, and a second stator for generating shock wave loss and rapidly raising the temperature of process gas; a biomass particle inlet is located at the end of the shock wave preheating section for mixing biomass particles with the gas heated by the shock wave; a pyrolysis chamber, which includes a cylindrical section and a conical section. The shock wave preheating section is tangentially connected to the pyrolysis chamber at the upper part of the cylindrical section; the biomass particles and high-temperature gas form a vortex in the cylindrical section, and pyrolysis is carried out in the vortex state, while gas-solid separation is carried out in the conical section.

Description

Technical Field

[0001] This invention relates to the field of biomass pyrolysis for bio-oil production technology, and particularly to a shock wave vortex device and method for biomass flash pyrolysis. Background Technology

[0002] In the production of bio-oil from biomass, conventional equipment commonly used in existing technologies includes falling bed and spiral bed systems. During the production process, pyrolysis time is a critical factor. When the pyrolysis time is too long, long-chain heavy components are prone to coking and polymerization into solids, reducing the oil yield. In addition, conventional equipment relies on the gravity of the particles themselves and the spiral rotation speed, resulting in slow gas-solid movement and low throughput, which also restricts further scale-up of the process. At the same time, conventional equipment relies on electric heating or partial combustion oxidation of the raw materials for heating, resulting in uneven gas-solid heating and a slow heating rate. Local overheating can easily cause the bio-oil to decompose into low-quality small molecule substances, such as methane and carbon monoxide, further reducing the oil yield.

[0003] For example, Chinese patent application CN116622399A discloses a method and apparatus for producing hydrocarbon-rich bio-oil through graded upgrading of biomass. This includes using a solid heat carrier as a primary upgrading catalyst to heat and catalyze biomass for pyrolysis and ketylation and aldol condensation reactions of the gaseous products from the primary pyrolysis, thereby increasing the bio-oil yield while adsorbing and capturing dust, alkali metals, and alkaline earth metals from the gaseous products of the primary pyrolysis. It also includes using a solid heat carrier as a secondary upgrading catalyst to subsequently deoxygenate and reform the gaseous products after primary catalytic upgrading into high-octane hydrocarbons, improving the quality of the bio-oil. This type of scheme uses a conventional moving bed reactor, where the gas-solid movement speed is slow (relying solely on the gravity of the particles), and the pyrolysis still employs traditional heating methods, resulting in uneven heating of the gas and solid components and a slow heating rate.

[0004] Shock waves demonstrate unique advantages for gas heating. First, through shock wave loss phenomena, uniform heating of the gas can be achieved within microseconds, ensuring the reaction occurs entirely at the set temperature. Second, shock wave heating of gas does not require consideration of the heating wall's temperature tolerance, resulting in a high upper temperature limit for the heated gas; it can be considered a "microwave oven" for gas. The inventors have discovered that shock wave pyrolysis is a relatively ideal endogenous heat-generating rapid pyrolysis technology, suitable for high-temperature, short-continuity scenarios. However, the complexity of the shock wave generator's structure makes it difficult to apply in gas-solid two-phase reaction scenarios, as solid particles and tar droplets can collide with the shock wave generator, severely impacting reactor lifespan and operational safety.

[0005] Therefore, there is an urgent need for a shock wave cyclone device and method for biomass flash pyrolysis, which can decouple the shock wave heating process from the raw material reaction process, effectively avoiding the problem that the biomass pyrolysis time is too long and the local heating is uneven, thus affecting the subsequent bio-oil yield.

[0006] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0007] The purpose of this invention is to provide a shock wave vortex device and method for biomass flash pyrolysis. The gas is heated separately by a shock wave in the preheating section, and then the heated high-speed gas is mixed with biomass particles and pyrolyzed in a vortex state in the pyrolysis chamber. This not only avoids the damage that may be caused by solid particles coming into contact with the shock wave generating device, but also effectively shortens the pyrolysis time and avoids the problem of uneven local heating.

[0008] To achieve the above objectives, according to a first aspect of the present invention, the present invention provides a shock wave cyclone device for biomass flash pyrolysis, comprising at least: a shock wave preheating section, which is a furnace tube structure with constricted ends, the furnace tube including a shell and a rotating shaft of the same shape as the shell disposed inside the shell, the circumferential gap between the rotating shaft and the shell forming a gas channel; in the gas channel, at corresponding positions along the gas flow direction in the straight section of the furnace tube, there are sequentially arranged: a first stator for preliminary acceleration of process gas, a rotor for accelerating process gas to supersonic speed, and a second stator for generating shock wave loss and rapidly raising the temperature of process gas; a biomass particle inlet disposed at the end of the shock wave preheating section for mixing biomass particles with gas heated by the shock wave; a pyrolysis chamber including a cylindrical section and a conical section, the shock wave preheating section being tangentially connected to the pyrolysis chamber at the upper part of the cylindrical section; the biomass particles and high-temperature gas forming a cyclone in the cylindrical section, pyrolysis occurring in the cyclone state, and gas-solid separation occurring in the conical section.

[0009] Furthermore, in the above technical solution, the first stator can be fixed on the inner wall of the furnace tube shell and is composed of multiple radially extending curved first grid blades; the rotor can be fixed on the rotating shaft and is composed of multiple radially extending curved second grid blades, and the rotor is located at an adjacent position downstream of the first stator airflow; the second stator can be fixed on the inner wall of the shell and is composed of multiple radially extending curved third grid blades, and the second stator is located at an adjacent position downstream of the rotor airflow.

[0010] Furthermore, in the above technical solution, the bending directions of the first and third grid leaves at corresponding positions are the same, while the bending directions of the first and second grid leaves at corresponding positions are opposite.

[0011] Furthermore, in the above technical solution, the gas channel constructed by the first grid leaf is a tapered structure; the gas channel constructed by the second grid leaf is the narrowest in the middle and gradually expands towards both ends; and the gas channel constructed by the third grid leaf is a gradually expanding structure.

[0012] Furthermore, in the above technical solution, the blade profile parameters of the first, second, and third grating blades can be set according to the process gas heating temperature requirements.

[0013] Furthermore, in the above technical solution, the height-to-diameter ratio of the cylindrical section of the pyrolysis chamber can be set according to the pyrolysis time of the biomass particles.

[0014] Furthermore, in the above technical solution, the bottom of the conical section of the pyrolysis chamber may be provided with a connected feed pipe for discharging or recycling the residual carbon particles after the biomass pellets are pyrolyzed.

[0015] Furthermore, in the above technical solution, multiple radially extending curved fourth grid blades are provided at the connection between the conical section and the feed pipe for further gas-solid separation.

[0016] Furthermore, in the above technical solution, there can be multiple shock wave preheating sections, which are evenly spaced along the circumference of the pyrolysis chamber.

[0017] Furthermore, in the above technical solution, a bio-oil outlet pipe can be provided at the top of the pyrolysis chamber for discharging the produced gaseous crude bio-oil product; a cylindrical metal mesh can be provided below the bio-oil outlet pipe for filtering ash particles and residual carbon particles entrained in the gaseous bio-oil.

[0018] To achieve the above objectives, according to a second aspect of the present invention, a shock vortex method for biomass flash pyrolysis is provided, employing the aforementioned apparatus, comprising at least the following steps: A) A process gas is introduced as a carrier gas into a shock preheating section, and the process gas is accelerated to supersonic speed by a rotor after initial acceleration by a first stator; B) The supersonic process gas generates shock wave losses in a second stator, the temperature of the process gas is rapidly increased, and its velocity is reduced; C) The subsonic high-temperature gas mixes with biomass particles at the outlet of the second stator, and the high-temperature, high-speed gas carrying the particles enters the pyrolysis chamber tangentially; D) The high-speed gas-solid mixture rotates downward along the inner wall of the cylindrical section of the pyrolysis chamber, and the biomass particles undergo pyrolysis in a vortex state, producing crude bio-oil product which is discharged into the gas phase through a bio-oil outlet pipe for further catalytic reforming, while the gas-solid mixture undergoes preliminary gas-solid separation in a conical section.

[0019] Furthermore, in the above technical solution, the method may also include: E, the downward rotating fluid after preliminary gas-solid separation undergoes further gas-solid separation through the fourth grid blade, and the solid residual carbon particles enter the feed pipe and are discharged; if the residual carbon particles are not completely pyrolyzed, cyclic pyrolysis is performed.

[0020] Furthermore, in the above technical solution, the temperature of the process gas in step B can be rapidly raised to 500-550℃.

[0021] Furthermore, in the above technical solution, the residence time of biomass pellets in the pyrolysis chamber is preferably 0.5-1 second.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1) The inventors discovered that during biomass pyrolysis using shock wave heating, the shock wave heating and endothermic reaction are not completed simultaneously. The rate of shock wave heating > the rate of endothermic gas-phase reaction > the rate of endothermic gas-solid reaction, meaning that shock wave heating can be completed instantaneously (in microseconds). This provides a theoretical basis for decoupling the shock wave heating process from the raw material pyrolysis reaction. Based on this, the present invention places the biomass feed inlet in the gas channel after shock wave heating, which not only does not affect the pyrolysis efficiency but also effectively avoids the impact of solid particles and tar droplets on the shock wave generating device.

[0024] 2) This invention, by setting a straight section including a first stator, a rotor, and a second stator in the furnace tube of the shock wave preheating section, generates a shock wave effect in the process gas during the operation of the gas channel. The gas is initially accelerated at the first stator, and the rotation of the rotor accelerates the raw gas to supersonic speed. Then, shock wave loss is generated at the second stator, and the temperature of the process gas is instantly raised, thereby achieving the purpose of rapid and uniform heating of the process gas. Compared with the traditional heating method, it avoids the decrease in oil quality and yield caused by the partial biomass combustion heating method of introducing air, and at the same time accelerates the heating speed, avoiding the problems of slow heating speed and uneven gas heating caused by external heating of the process gas in the furnace tube.

[0025] 3) This invention utilizes a shock wave preheating section tangentially connected to the pyrolysis chamber at the top of the cylindrical section. This allows a high-speed, high-temperature gas flow carrying biomass particles to swirl downwards along the inner wall of the pyrolysis chamber. Pyrolysis occurs within the cylindrical section under swirling conditions, followed by gas-solid separation in the conical section. This significantly shortens the gas-solid contact time, reduces the coking and polymerization reactions of long-chain heavy components, and effectively improves the bio-oil yield. Simultaneously, the tangential entry into the inner wall of the cylindrical section results in a swirling gas-solid flow with constantly changing direction and periodically altering the velocity difference between gas and solids. This achieves a high-speed, strong coupling process of swirling flow, providing a large amount of heat for the pyrolysis of biomass particles in a short time, increasing the rate of volatile release, and further improving the bio-oil yield.

[0026] 4) The preheating stage of this invention is only for gases, which can achieve "high temperature and short residence" of process gases in the shock wave preheating section. The internal heat generation method makes the gas temperature higher than the furnace tube temperature. Compared with existing furnace tubes, the existence of the boundary layer between the tube wall and the gas changes from a negative effect of hindering heat transfer to a positive effect of protecting the furnace tube. Therefore, when using furnace tubes of the same material, the device of this invention can withstand higher temperatures and provide more heat for the pyrolysis reaction. The "short residence" can create conditions for decoupling shock wave heating and biomass pyrolysis, realizing "heating the gas first, and then mixing the gas and solid for the pyrolysis of biomass particles".

[0027] 5) This invention uses a high-speed airflow to carry particles into the pyrolysis chamber for cyclone pyrolysis. When the throughput is large, it solves the problem that conventional devices rely on the gravity of the particles themselves and the speed of the spiral, resulting in slow gas-solid movement and low throughput, which helps to scale up the process.

[0028] 6) This invention uses electricity (i.e., electrifying the rotor to create a shock wave effect) instead of fossil fuels to achieve the high temperatures required in the production process. Compared with combustion heating technology, it can reduce carbon dioxide emissions, and the saved fuel can be used to prepare high value-added products or as raw materials.

[0029] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it according to the contents of the specification, and to make the above and other objects, technical features and advantages of the present invention easier to understand, one or more preferred embodiments are listed below and described in detail with reference to the accompanying drawings. Attached Figure Description

[0030] Figure 1 This is a perspective view of the first embodiment of the shock wave vortex device of the present invention.

[0031] Figure 2 This is a longitudinal cross-sectional schematic diagram of the shock wave preheating section in the shock wave vortex device of the present invention (showing the airflow direction).

[0032] Figure 3 This is a three-dimensional structural schematic diagram of the furnace tube shell of the shock wave preheating section of the present invention (showing the first stator and the second stator).

[0033] Figure 4 This is a three-dimensional structural schematic diagram of the furnace tube rotating shaft of the shock wave preheating section of the present invention (showing the rotor).

[0034] Figure 5 This is a perspective view of the overall structure of the shock wave preheating section furnace tube of the present invention (including the shell and the rotating shaft).

[0035] Figure 6 This is a schematic diagram of the overall structure of the first stator in the shock wave preheating section of the present invention (showing the first grid blade).

[0036] Figure 7 This is a schematic diagram of the overall rotor structure in the shock wave preheating section of the present invention (showing the second grid blade).

[0037] Figure 8 This is a schematic diagram of the overall structure of the second stator in the shock wave preheating section of the present invention (showing the third grid blade).

[0038] Figure 9 This is a schematic diagram of the blade cascades of the first stator, rotor, and second stator in the shock wave preheating section of the present invention (showing the air profile parameter data of each blade cascade).

[0039] Figure 10 This is a three-dimensional perspective view of the second embodiment of the shock wave vortex device of the present invention.

[0040] Figure 11 yes Figure 10 Top view.

[0041] Explanation of key figure labels:

[0042] 100 / 200 - Shockwave vortex device; 101 - Preheating section gas inlet; 102 - Biomass pellet inlet; 103 - Bio-oil outlet;

[0043] 1-Shock wave preheating section, 10-Furnace tube shell, 11-Rotating shaft, 12-Gas passage, 13-First stator, 131-First grid blade, 14-Rotor, 141-Second grid blade, 15-Second stator, 151-Third grid blade, 2-Pyrolysis chamber, 21-Cylindrical section, 22-Conical section, 23-Feeding pipe, 24-Fourth grid blade. Detailed Implementation

[0044] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0045] Unless otherwise expressly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "comprises" shall be understood to include the stated elements or components without excluding other elements or other components.

[0046] In this document, for ease of description, spatial relative terms such as “below,” “under,” “down,” “above,” “above,” “upper,” etc., are used to describe the relationship of one element or feature to another element or feature in the accompanying drawings. It should be understood that spatial relative terms are intended to encompass different orientations of an object in use or operation, in addition to those depicted in the figures. For example, if an object in the figure is flipped, an element described as “below” or “under” another element or feature would be oriented “above” that element or feature. Thus, the exemplary term “below” can encompass both the downward and upward orientations. An object may also have other orientations (rotated 90 degrees or other orientations), and the spatial relative terms used herein should be interpreted accordingly.

[0047] In this document, the terms "first," "second," etc., are used to distinguish two different elements or parts, and are not used to define specific positions or relative relationships. In other words, in some embodiments, the terms "first," "second," etc., can also be used interchangeably.

[0048] The inventors discovered that shock wave heating offers unique advantages for heating gases, enabling uniform heating and achieving high temperatures. However, in the process of producing bio-oil from biomass pyrolysis, since the biomass feedstock is composed of solid particles, if a gas-solid mixture is introduced into the shock wave generator for simultaneous shock wave heating and biomass pyrolysis, the high gas velocity (nearly supersonic) causes significant impact from the solid particles carried in the gas on the shock wave generator. This means that biomass solid particles and generated tar droplets collide with the shock wave generator, severely impacting its lifespan and operational safety. Further research revealed that during biomass pyrolysis using shock wave heating, the shock wave heating and endothermic reaction are not simultaneous. The rate of shock wave heating > the rate of endothermic gas-phase reaction > the rate of endothermic gas-solid reaction. This means that shock wave heating can be completed instantaneously (on the microsecond scale), providing a theoretical basis for decoupling the shock wave heating process from the feedstock pyrolysis reaction. Therefore, the present invention places the biomass feed inlet in the gas channel after shock wave heating, which not only does not affect the pyrolysis efficiency, but also effectively avoids the impact of solid particles and tar droplets on the shock wave generating device.

[0049] like Figures 1 to 5As shown, the present invention provides a shock vortex device 100 for biomass flash pyrolysis (first embodiment), comprising at least a shock preheating section 1 and a pyrolysis chamber 2. The shock preheating section 1 is a furnace tube structure with constricted ends (i.e., the shock wave generating device of the present invention). The furnace tube includes a shell 10 and a rotating shaft 11 of the same shape as the shell, disposed within the shell 10. The circumferential gap between the rotating shaft 11 and the shell 10 forms a gas channel 12. In the gas channel 12, at corresponding positions along the gas flow direction in the straight section of the furnace tube, are sequentially arranged: a first stator 13 for initial acceleration of the process gas, a rotor 14 for accelerating the process gas to supersonic speed, and a second stator 15 for generating shock wave losses and rapidly raising the temperature of the process gas. A biomass pellet inlet 102 is located at the end of the shock preheating section for mixing the biomass pellets with the shock-heated gas. The pyrolysis chamber 2 includes a cylindrical section 21 and a conical section 22. The shock wave preheating section 1 is tangentially connected to the pyrolysis chamber 2 at the upper part of the cylindrical section 21. Biomass particles and high-temperature gas form a swirling flow in the cylindrical section 21, and pyrolysis is carried out in the swirling flow state. Gas-solid separation is carried out in the conical section 22.

[0050] In the above-described technical solution of the present invention, by setting a first stator, a rotor, and a second stator in a straight section within the furnace tube, the process gas (preferably nitrogen) generates a shock wave effect during its operation in the gas channel. It is initially accelerated at the first stator, and the rotation of the rotor accelerates the raw material gas to supersonic speeds. This results in shock wave loss at the second stator, instantly raising the temperature of the process gas, thereby achieving rapid and uniform heating of the process gas. Compared to traditional heating methods, this avoids the decrease in oil quality and yield caused by partially burning biomass with air, while simultaneously accelerating the heating rate and avoiding the problems of slow heating and uneven gas heating caused by externally heating the process gas in the furnace tube. Furthermore, by placing the biomass pellet inlet at the end of the shock wave preheating section (i.e., at the rear end of the shock wave generator), the heating of the shock wave and the biomass pellet are combined. By decoupling the shockwave technology and successfully applying it to the gas-solid two-phase field, the system not only avoids the impact of solid particles and tar droplets on the stator and rotor but also maintains the subsequent pyrolysis efficiency. Furthermore, by tangentially connecting the shockwave preheating section to the pyrolysis chamber at the top of the cylindrical section, a high-speed, high-temperature gas flow carrying biomass particles swirls downwards along the inner wall of the pyrolysis chamber. Pyrolysis occurs within the cylindrical section under swirling conditions, followed by gas-solid separation in the conical section. This significantly shortens the gas-solid contact time, reduces the coking and polymerization reactions of long-chain heavy components, and effectively improves the bio-oil yield. Simultaneously, the tangential entry into the inner wall of the cylindrical section creates a swirling flow with constantly changing direction, periodically altering the velocity difference between gas and solid, achieving a high-speed, strongly coupled swirling process. This provides a large amount of heat for the pyrolysis of biomass particles in a short time, increasing the rate of volatile release and further improving the bio-oil yield.

[0051] Further as Figures 2 to 9 As shown, the first stator 13 is fixed to the inner wall of the furnace tube housing 10 and is composed of multiple radially extending curved first grid blades 131. The fixing method can be to insert the first grid blades 131 into the housing 10 and lock them in place. The rotor 14 is fixed to the rotating shaft 11 and is composed of multiple radially extending curved second grid blades 141. The fixing method can be to insert the second grid blades 141 into the rotating shaft 11 and lock them in place. The rotor is located downstream of the first stator 13 and adjacent to it. The second stator 15 is fixed to the inner wall of the furnace tube housing and is composed of multiple radially extending curved third grid blades 151. The second stator 15 is located downstream of the rotor 14 and adjacent to it.

[0052] Further as Figures 6 to 9 As shown, the first blade 131 and the third blade 151 at corresponding positions have the same bending direction, while the first blade 131 and the second blade 141 at corresponding positions have opposite bending directions. That is, the first blade 131, the second blade 141, and the third blade 151 are smoothly connected, facilitating rapid airflow. Furthermore, the gas channel constructed by the first blade 131 is a tapered structure (i.e., purely contractile); the gas channel constructed by the second blade 141 is a structure that is narrowest in the middle and gradually expands towards both ends (i.e., impingement type); and the gas channel constructed by the third blade 151 is a gradually expanding structure (i.e., purely expanding type). This structural arrangement is more conducive to the occurrence of shock wave loss effects at the second stator (the principle of shock wave generation is prior art and will not be detailed here). Preferably, but not limitingly, the airfoil parameters of the first blade 131, the second blade 141, and the third blade 151 in this embodiment are set according to the heating temperature of the process gas. The rotor 14 has the same width at both ends as the adjacent first stator 13 and second stator 15, and its height is preferably 70mm for both ends. Figure 9 The stator and rotor are planar unfolded structures. Table 1 shows the air profile parameters of the stator and rotor (parameter data are already labeled in...). Figure 9 middle).

[0053] Table 1 Leaf type parameters

[0054]

[0055]

[0056] After the shock wave loss effect is completed at the second stator 15 (that is, the gas suddenly decelerates through the gradual expansion structure of the second stator, while the supersonic gas from the rotor 14 behind it still maintains high speed and generates shock wave loss), the mixed gas is rapidly heated and the temperature rises, which can achieve the effect of uniform heating.

[0057] Further as Figure 1As shown, the aspect ratio of the cylindrical section 21 of the pyrolysis chamber can be set according to the pyrolysis time of the biomass pellets. That is, the number of rotations of the pellets in the pyrolysis chamber is set by the aspect ratio of the cylindrical section, thereby determining the residence time. The bottom of the conical section 22 of the pyrolysis chamber is provided with a feed pipe 23 for discharging or recycling the residual carbon particles after the pyrolysis of the biomass pellets. That is, the feed pipe 23 is used for discharging solid residual carbon particles and collecting residual carbon particles. The collected solid particles can be mixed back into the silo for secondary pyrolysis of particles with incomplete volatile matter removal. Preferably, but not limitingly, multiple radially extending curved fourth grid blades 24 are provided at the connection between the conical section 22 and the feed pipe 23 for further gas-solid separation. That is, the gas channel constructed by the fourth grid blades 24 can be a straight structure or an inclined structure to separate the gas-solid mixture from the conical section 22 of the pyrolysis chamber, achieving further gas-solid separation. The top of the pyrolysis chamber 2 is equipped with a bio-oil outlet pipe 103 for discharging the produced gaseous crude bio-oil product; a cylindrical metal mesh (not shown in the figure) is provided below the bio-oil outlet pipe 103 for filtering ash particles and residual carbon particles entrained in the gaseous bio-oil.

[0058] Further as Figure 10 and 11 As shown, the shock wave preheating section 1 of the present invention can be multiple and evenly spaced along the circumference of the pyrolysis chamber 2 (that is, the second embodiment of the shock wave vortex device 200 of the present invention). Two are shown in the figure. The way in which multiple shock wave preheating sections 1 enter the pyrolysis chamber tangentially can effectively increase the solid content in the pyrolysis chamber 2 and further increase the processing capacity of the device of the present invention.

[0059] refer to Figures 1 to 11 As shown, the present invention also provides a shock vortex method for biomass flash pyrolysis, the apparatus of which includes at least the following steps:

[0060] Step S101: Process gas (preferably nitrogen) is introduced into the shock wave preheating section 1 as a carrier gas. After the process gas is initially accelerated by the first stator 13, it is accelerated to supersonic speed by the rotor 14.

[0061] In step S102, the supersonic process gas generates shock wave loss at the second stator 15, rapidly increasing its temperature and decreasing its velocity. The temperature of the process gas in this invention can be rapidly increased to 500-550°C.

[0062] In step S103, the subsonic high-temperature gas mixes with the biomass pellets at the outlet of the second stator 15, and the high-temperature high-speed gas carrying the pellets enters the pyrolysis chamber 2 tangentially.

[0063] In step S104, the high-speed gas-solid mixture rotates downwards along the inner wall of the cylindrical section 21 of the pyrolysis chamber 2, and the biomass particles undergo pyrolysis in a swirling state. The residence time of the biomass particles in the pyrolysis chamber is preferably 0.5-1 seconds. The crude bio-oil product is discharged into the gas phase through the bio-oil outlet pipe 103 for the next step of catalytic reforming, while the gas-solid mixture undergoes preliminary gas-solid separation in the conical section 22.

[0064] The method of the present invention may further include:

[0065] In step S105, the downward rotating fluid after preliminary gas-solid separation undergoes further gas-solid separation via the fourth grid blade 24, and the solid residual carbon particles enter the feed pipe 23 and are discharged. If the residual carbon particles are not completely pyrolyzed, cyclic pyrolysis can be performed, that is, the collected solid particles can be mixed back into the silo to perform secondary pyrolysis on the particles that have not been completely desorbed of volatile matter.

[0066] The preheating stage of the method of this invention is only for gases, which can achieve "high temperature and short residence time" for process gases. First, the requirement of "high temperature" means that the highest temperature of the gas in the shock wave preheating section is about 100-300°C higher than the outlet temperature of a conventional tubular furnace with similar raw materials. This is also one of the main advantages of this invention. In the case of internal heat generation, the gas temperature is higher than the furnace tube temperature, while the temperature of a conventional flue gas thermal radiation furnace tube is higher than the gas temperature inside the tube. The existence of the boundary layer between the tube wall and the gas changes from a negative effect that hinders heat transfer to a positive effect that protects the furnace tube. Therefore, when using furnace tubes of the same material, the device of this invention can withstand higher temperatures, providing more heat for the pyrolysis reaction and increasing the yield of bio-oil. Second, "short residence time" refers to a short residence time, which creates conditions for decoupling shock wave heating and biomass pyrolysis, realizing "heating the gas first, and then mixing the gas and solid for the pyrolysis of biomass particles", without affecting the pyrolysis efficiency.

[0067] In addition, the method of the present invention carries particles into the pyrolysis chamber for cyclone pyrolysis via a high-speed airflow. When the throughput is large, it solves the problem that conventional devices rely on the particle's own gravity and the spiral rotation speed, resulting in slow gas-solid movement and low throughput, which is helpful for the scale-up of the process. The present invention uses electricity (i.e., electrifying the rotor to generate a shock wave effect) instead of fossil fuels to achieve the high temperature required in the production process. Compared with combustion heating technology, it can reduce carbon dioxide emissions, and the fuel saved can be used to prepare high value-added products or as raw materials.

[0068] The effects of the present invention are illustrated below with several specific embodiments:

[0069] Example 1

[0070] refer to Figure 1At room temperature, nitrogen gas is initially accelerated at the first stator 13, and the rotation of the rotor 14 accelerates the process gas to supersonic speed, thereby generating shock wave losses at the second stator 15 and instantly raising the temperature of the process gas to 500-550℃. Simultaneously, biomass pellets (pine waste) enter the end of the shock wave preheating section 1 from above via a feeding screw. The pellets are driven tangentially into the pyrolysis chamber 2 by the gas. The high-speed gas-solid fluid rotates downwards along the inner wall of the cylindrical section 21 of the pyrolysis chamber. Due to the shape of the cylinder wall, the velocity difference between the gas and solid fluids varies periodically, resulting in relative motion between the gas and solid. The pellets are gradually heated during rotation. High-temperature particles undergo pyrolysis to produce crude bio-oil product into the gas phase. The gas-solid fluid gradually separates into gas and solid within the conical section 22. The particles continue to rotate downwards along the pipe wall until they reach the feed pipe 23, while the gas is discharged through the bio-oil outlet pipe 103 at the pyrolysis chamber outlet. The crude bio-oil product yield is 54.5%. The crude bio-oil product undergoes further catalytic reforming to obtain refined bio-oil and other products. The continuously rotating gas-solid fluid is further divided and blocked by the fourth grid leaf 24, resulting in further gas-solid separation. Solid residual carbon particles enter the feed pipe 23 and are discharged from the device of this invention. The residence time of the particles in the pyrolysis chamber is 0.5 s.

[0071] Example 2

[0072] refer to Figure 1 At room temperature, nitrogen gas is initially accelerated at the first stator 13, and the rotation of the rotor 14 accelerates the process gas to supersonic speed. This generates shock wave losses at the second stator 15, instantly raising the temperature of the process gas to 500-550℃. Simultaneously, biomass pellets (pine waste) and molecular sieve catalyst are premixed and fed from above through a feeding screw into the end of the shock wave preheating section 1. The pellets are driven tangentially into the pyrolysis chamber 2 by the gas. The high-speed gas-solid fluid rotates downwards along the inner wall of the cylindrical section 21 of the pyrolysis chamber. Due to the shape of the cylinder wall, the velocity difference between the gas and solid fluids varies periodically, resulting in relative motion between the gas and solid phases. The pellets gradually heat up, and during rotation, the high-temperature pellets undergo pyrolysis, producing crude bio-oil product in the gas phase. The particles continue to contact with the molecular sieve catalyst and undergo swirling motion in the pyrolysis chamber, where they are in-situ catalytically reformed into refined bio-oil. The gas-solid fluid gradually separates within the conical section 22, and the particles continue to rotate downwards along the pipe wall until they reach the feed pipe 23. The gas is discharged through the bio-oil outlet pipe 103, resulting in a low-carbon aromatic bio-oil yield of 25.3%. The continuously rotating gas-solid fluid is further divided and blocked by the fourth grid leaf 24, leading to further gas-solid separation. Solid residual carbon particles and the molecular sieve catalyst enter the feed pipe 23 and are discharged from the device of this invention. The residence time of the particles in the pyrolysis chamber 2 is 1 second. The discharged particles undergo flotation, with lighter residual carbon and ash particles being discharged, while the heavier catalyst re-enters the silo and premixes with fresh raw materials.

[0073] Example 3

[0074] refer to Figure 10 The pyrolysis oil yield is improved by using two shock wave preheating sections 1 that enter the pyrolysis chamber 2 tangentially and increasing the solid content in the pyrolysis chamber through two spiral gas-solid fluids.

[0075] At room temperature, nitrogen gas of the same flow rate is initially accelerated at the first stator 13 of the two shock wave preheating sections 1. The rotation of the rotor 14 accelerates the process gas to supersonic speed, thereby generating shock wave losses at the second stator 15 and instantly raising the temperature of the process gas to 500-550℃. Simultaneously, biomass pellets (pine waste) enter the end of the shock wave preheating section 1 from above via a feeding screw. The pellets are driven tangentially by the gas into the pyrolysis chamber 2. The high-speed gas-solid fluid rotates downwards along the inner wall of the cylindrical part 21 of the pyrolysis chamber. Due to the shape of the cylinder wall, the velocity difference between the gas and solid fluids varies periodically, resulting in relative motion between the gas and solid. The pellets are gradually subjected to... In the heat-generating process, the high-temperature particles undergo pyrolysis during rotation, producing crude bio-oil product into the gas phase. The gas-solid fluid gradually separates within the conical section 22. A portion of the gas and particles continue to rotate downwards along the pipe wall until reaching the feed pipe 23, while the other portion of the gas is discharged through the bio-oil outlet pipe 103. The crude bio-oil product yield is 60.2%. The crude bio-oil product undergoes further catalytic reforming to obtain refined bio-oil and other products. The gas-solid fluid, which continues to rotate downwards, is further divided and blocked by the fourth grid leaf 24, resulting in further gas-solid separation. Solid residual carbon particles enter the feed pipe 23 and are discharged from the device of this invention. The residence time of the particles in the pyrolysis chamber is 0.5 s.

[0076] The foregoing description of specific exemplary embodiments of the present invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. Any simple modifications, equivalent changes, and alterations made to the foregoing exemplary embodiments should fall within the scope of protection of the present invention.

Claims

1. A shock vortex device for biomass flash pyrolysis, characterized in that, include: The shock wave preheating section is a furnace tube structure with constricted ends. The furnace tube includes a shell and a rotating shaft with the same shape as the shell inside the shell. The circumferential gap between the rotating shaft and the shell forms a gas channel. In the gas channel, at the corresponding position of the straight section of the furnace tube, along the gas flow direction, there are sequentially arranged: a first stator for initial acceleration of process gas, a rotor for accelerating process gas to supersonic speed, and a second stator for generating shock wave loss and rapidly raising the temperature of process gas. The biomass pellet inlet is located at the end of the shock wave preheating section to mix the biomass pellets with the gas heated by the shock wave. The pyrolysis chamber includes a cylindrical section and a conical section. The shock wave preheating section is tangentially connected to the pyrolysis chamber at the upper part of the cylindrical section. Biomass particles and high-temperature gas form a swirling flow in the cylindrical section, and pyrolysis is carried out in the swirling flow state. Gas-solid separation is carried out in the conical section.

2. The shockwave vortex device for biomass flash pyrolysis according to claim 1, characterized in that, The first stator is fixed to the inner wall of the furnace tube housing and is composed of a plurality of radially extending curved first grid blades; the rotor is fixed to the rotating shaft and is composed of a plurality of radially extending curved second grid blades, and the rotor is located at an adjacent position downstream of the first stator airflow; the second stator is fixed to the inner wall of the housing and is composed of a plurality of radially extending curved third grid blades, and the second stator is located at an adjacent position downstream of the rotor airflow.

3. The shock vortex device for biomass flash pyrolysis according to claim 2, characterized in that, The first and third grid blades at corresponding positions have the same bending direction, while the first and second grid blades at corresponding positions have opposite bending directions.

4. The shock vortex device for biomass flash pyrolysis according to claim 3, characterized in that, The gas channel constructed by the first grating blade has a tapered structure; the gas channel constructed by the second grating blade has a structure that is narrowest in the middle and gradually expands towards both ends; the gas channel constructed by the third grating blade has a gradually expanding structure.

5. The shock vortex device for biomass flash pyrolysis according to claim 4, characterized in that, The blade profile parameters of the first, second, and third grating blades are set according to the heating temperature requirements of the process gas.

6. The shock vortex device for biomass flash pyrolysis according to claim 1, characterized in that, The height-to-diameter ratio of the cylindrical section of the pyrolysis chamber is set according to the pyrolysis time of the biomass particles.

7. The shock vortex device for biomass flash pyrolysis according to claim 1, characterized in that, The bottom of the conical section of the pyrolysis chamber is equipped with a feed pipe for discharging or recycling the residual carbon particles after the biomass pellets are pyrolyzed.

8. The shock vortex device for biomass flash pyrolysis according to claim 7, characterized in that, The conical section is provided with multiple radially extending curved fourth grid blades at the connection between the conical section and the feed pipe for further gas-solid separation.

9. The shock vortex device for biomass flash pyrolysis according to claim 1, characterized in that, The shock wave preheating section consists of multiple sections, which are evenly spaced along the circumference of the pyrolysis chamber.

10. The shockwave vortex device for biomass flash pyrolysis according to claim 1, characterized in that, The top of the pyrolysis chamber is equipped with a bio-oil outlet pipe for discharging the produced gaseous crude bio-oil product; a cylindrical metal mesh is provided below the bio-oil outlet pipe for filtering ash particles and residual carbon particles entrained in the gaseous bio-oil.

11. A shock vortex method for biomass flash pyrolysis, characterized in that, The apparatus described in any one of claims 1 to 10 comprises the following steps: A. The process gas is introduced into the shock wave preheating section as a carrier gas. After the process gas is initially accelerated by the first stator, it is accelerated to supersonic speed by the rotor. B. The supersonic process gas generates shock wave losses in the second stator, and the temperature of the process gas is rapidly increased while its velocity is reduced. C. The subsonic high-temperature gas mixes with the biomass pellets at the outlet of the second stator, and the high-temperature, high-speed gas carrying the pellets enters the pyrolysis chamber tangentially. D. The high-speed gas-solid mixture rotates downward along the inner wall of the cylindrical section of the pyrolysis chamber. The biomass particles are pyrolyzed in a swirling state, and the crude bio-oil product is discharged into the gas phase through the bio-oil outlet pipe for the next step of catalytic reforming. The gas-solid mixture undergoes preliminary gas-solid separation in the conical section.

12. The shock vortex method for biomass flash pyrolysis according to claim 11, characterized in that, Also includes: E. The downward-rotating fluid after the initial gas-solid separation undergoes further gas-solid separation via the fourth grid blade, with solid residual carbon particles entering the feed pipe and being discharged. Cyclic pyrolysis is carried out when the residual carbon particles are not completely pyrolyzed.

13. The shock vortex method for biomass flash pyrolysis according to claim 11, characterized in that, In step B, the temperature of the process gas is rapidly raised to 500-550°C.

14. The shock vortex method for biomass flash pyrolysis according to claim 11, characterized in that, The residence time of the biomass particles in the pyrolysis chamber is 0.5-1 second.

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