Shockwave cyclone device and method for hydrogen production from biomass

Abstract

The application discloses a shock wave cyclone device and method for hydrogen production from biomass, which comprises at least a shock wave preheating section, which is a furnace tube structure with two end necking, the furnace tube comprises a shell and a rotating shaft arranged in the shell and with the same shape as the shell, the annular gap between the rotating shaft and the shell forms a gas channel; in the gas channel, corresponding positions of the straight section of the furnace tube are sequentially provided with a first stator for preliminary acceleration of process gas, a rotor for accelerating the process gas to supersonic speed and a second stator for generating shock wave loss and rapidly lifting the temperature of the process gas along the gas flow direction; a biomass particle inlet is arranged at the end of the shock wave preheating section, which is used for mixing the biomass particles with the gas heated by the shock wave; a gasification chamber comprises a cylindrical section and a conical section, the shock wave preheating section is tangentially communicated with the gasification chamber at the upper part of the cylindrical section; the biomass particles and the high-temperature gas form a cyclone in the spiral channel of the cylindrical section and the conical section, gasification is carried out in the cyclone state to generate hydrogen-rich synthesis gas, and gas-solid separation is carried out in the conical section.

Description

Technical Field

[0001] This invention relates to the field of biomass hydrogen production technology, and in particular to a shock wave vortex device and method for biomass hydrogen production. Background Technology

[0002] As a highly efficient and clean energy source, hydrogen energy development is timely. The carbon emissions generated during the production of hydrogen using biomass as a raw material are not included in carbon accounting, and the produced hydrogen is green hydrogen. Traditional top- or bottom-draft moving bed and dual fluidized bed processes use the combustion of some product gas or fixed carbon to provide heat for the gasification or reforming reaction. Sometimes, additional fuel is needed to supplement the reactor's heat, resulting in significant carbon dioxide emissions and wasting light fuels. Furthermore, due to the higher heat capacity of water vapor and the lower heat capacity of nitrogen, dual fluidized bed fluidization requires water vapor mixed with nitrogen as the fluidizing gas, while moving bed heating requires air gasification to reduce the consumption of syngas and light fuels. However, this introduces nitrogen into the reaction system, creating difficulties for subsequent separation. In addition, uneven heating leads to increased secondary reactions, making coking and carbon buildup more likely, requiring frequent replacement and maintenance, thus limiting the unit's operating cycle. Moreover, conventional units rely on particle gravity, low-speed airflow, and spiral rotation for gasification, resulting in slow gas-solid movement and low throughput, which also limits further scale-up of the process.

[0003] Chinese patent application CN114180521A discloses a biomass hydrogen production system and method. The method involves carbonizing biomass feedstock with nitrogen at 450-550°C to prepare biochar; activating the biochar with alkaline solution steam and nitrogen at 850°C to prepare a biochar catalyst; activating the biochar at 700-800°C under conditions of water vapor and CO2 gas to generate a biochar adsorbent for adsorption; gasifying the biomass feedstock, steam, nitrogen, and oxygen at 800°C to generate gas and gaseous tar; reforming the gas and gaseous tar at 1000°C using the biochar catalyst; and then subjecting the reformed gas to pressure swing adsorption using the biochar adsorbent to obtain high-purity hydrogen. This method can effectively increase the H2 and CO yields from biomass gasification. Compared to other catalysts, the biochar catalyst for tar reforming can increase hydrogen yield, with the hydrogen content in the gasified gas reaching 80%-90%.

[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 hydrogen production, which can decouple the shock wave heating process from the raw material reaction process. This can effectively solve the problems of increased secondary reactions and easy carbon buildup caused by uneven heating, as well as the problem of subsequent product separation caused by the introduction of nitrogen. At the same time, it can further increase the processing capacity of the device and improve the economic efficiency of the route.

[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 cyclone device and method for biomass hydrogen production. The process gas is heated separately by a shock wave in the preheating section, and then the heated high-speed process gas is mixed with biomass particles and vaporized in a cyclone state in the gasification chamber. This not only avoids the damage that may be caused by solid particles contacting the shock wave generator, but also effectively solves the problems of increased secondary reactions and easy carbon buildup caused by uneven heating, and avoids the subsequent product separation problems caused by the introduction of nitrogen.

[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 hydrogen production, 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 gasification chamber including a cylindrical section and a conical section, the shock wave preheating section being tangentially connected to the gasification chamber at the upper part of the cylindrical section; the biomass particles and high-temperature gas forming a cyclone in the spiral channel of the cylindrical section and the conical section, gasifying to generate hydrogen-rich synthesis gas in the cyclone state, and performing gas-solid separation 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 a plurality of radially extending curved first grid blades; the rotor can be fixed on 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 can be fixed on the inner wall of the shell 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.

[0010] Furthermore, in the above technical solution, the bending directions of the first and third grid blades at corresponding positions are the same, while the bending directions of the first and second grid blades 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 gasification chamber can be set according to the gasification time of the biomass pellets. The number of rotations of the pellets in the gasification chamber is set by the height-to-diameter ratio of the cylindrical section, thereby determining the residence time of the biomass pellets in the gasification chamber.

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

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

[0016] Furthermore, in the above technical solution, the spiral channel can be fixed on the inner wall of the gasification chamber and extend downwards in a spiral manner to divide the swirling gas-solid fluid at different heights into zones, thereby avoiding back mixing between gas-solid fluids with different degrees of gasification.

[0017] Furthermore, in the above technical solution, a product gas outlet pipe may be provided at the top of the gasification chamber for discharging the produced hydrogen-rich synthesis gas; a cylindrical metal mesh may be provided below the product gas outlet pipe for filtering ash particles and residual carbon particles entrained in the product gas.

[0018] To achieve the above objectives, according to a second aspect of the present invention, the present invention provides a shock vortex method for biomass hydrogen production, employing the aforementioned apparatus, and comprising at least the following steps: A. Process gas is introduced into a shock preheating section, and the process gas is accelerated to supersonic speed by the rotor after initial acceleration by the first stator; B. The supersonic process gas generates shock wave losses in the second stator, the temperature of the process gas is rapidly increased, and the velocity is reduced; C. Subsonic high-temperature gas is mixed with biomass particles at the outlet of the second stator, and the high-temperature, high-speed gas carrying the particles enters the gasification chamber tangentially; D. The high-speed gas-solid mixture rotates downward along a spiral channel provided in the gasification chamber, and the biomass particles are gasified in a vortex state. The produced hydrogen-rich synthesis gas is discharged into the gas phase through a product gas outlet pipe for further purification, 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 gasified, they are subjected to circulating gasification.

[0020] Furthermore, in the above technical solution, the process gas is water vapor; the hydrogen-rich synthesis gas contains hydrogen, methane, and carbon monoxide.

[0021] Furthermore, in the above technical solution, the number of turns of the spiral channel, the height-to-diameter ratio of the cylindrical section of the gasification chamber, and the residence time of the biomass pellets have the following relationship:

[0022]

[0023] Where n is the number of turns in the spiral channel; h is the height of the cylindrical section (m); v is the gas velocity entering the spiral channel (m / s); β is the height-to-diameter ratio of the cylindrical section; t is the residence time of the biomass pellets (s); m is the feed rate of the biomass pellets (kg); and k is the biomass pellet gasification rate (s). -1 .

[0024] Furthermore, in the above technical solution, the temperature of the process gas in step B can be rapidly raised to 650-850℃.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1) The inventors discovered that during biomass gasification and 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 feedstock gasification and pyrolysis reaction. Based on this, the present invention places the biomass feed inlet in the gas channel after shock wave heating. This not only does not affect the gasification and pyrolysis efficiency but also effectively avoids the impact of solid particles and tar droplets on the shock wave generator. In other words, by decoupling the shock wave heating from the heated gasification of biomass particles, shock wave technology is successfully applied to the gas-solid two-phase field. In addition, water vapor serves as an external hydrogen source, which can promote the system to move in the direction of producing more hydrogen, thus improving the quality of syngas.

[0027] 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, allows water vapor to generate a shock wave effect during the operation of the gas channel. It is initially accelerated at the first stator, and the rotation of the rotor accelerates the water vapor to supersonic speed. Then, shock wave loss is generated at the second stator, and the temperature of the water vapor 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 syngas quality and yield and the subsequent nitrogen separation problem caused by the introduction of air or oxygen-enriched gas for partial biomass combustion heating. At the same time, it accelerates the heating speed and avoids the problems of slow heating speed and uneven gas heating caused by external heating of the process gas in the furnace tube.

[0028] 3) This invention utilizes a shock wave preheating section tangentially connected to the gasification 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 spiral channel of the gasification chamber. Gasification occurs within the spiral channel, followed by gas-solid separation in the conical section. This significantly shortens the gas-solid contact time and allows for the partitioning of the swirling gas-solid fluids at different heights, preventing back-mixing between fluids with different gasification levels. Simultaneously, the tangential entry into the inner wall of the cylindrical section results in a swirling gas-solid flow with constantly changing direction, periodically altering the velocity difference between the gas and solid components. This achieves a high-speed, strong coupling process of the swirling flow, providing a large amount of heat for the gasification of biomass particles in a short time, increasing the rate of volatile release, and thus further improving the yield of hydrogen-rich syngas.

[0029] 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 gasification and pyrolysis reaction. The "short residence" can create conditions for decoupling shock wave heating and biomass gasification and pyrolysis, realizing "heating the gas first, and then mixing the gas and solid for biomass particle gasification".

[0030] 5) The inventors discovered that the residence time of biomass pellets in the gasification chamber is related to the aspect ratio of the cylindrical section and the number of rotations of the spiral channel. By understanding the relationship between the number of turns of the spiral channel, the aspect ratio of the cylindrical section of the gasification chamber, and the residence time of the biomass pellets, the aspect ratio of the gasification chamber and the number of turns of the spiral channel can be designed according to process requirements to control the residence time of biomass pellets in the gasification chamber, thereby ensuring the yield of hydrogen-rich syngas.

[0031] 6) This invention uses a high-speed airflow to carry particles into the gasification chamber for cyclone gasification and pyrolysis. When the throughput is large, it solves the problem that conventional devices rely on the particle's own gravity and the spiral speed, resulting in slow gas-solid movement and low throughput, which helps to scale up the process.

[0032] 7) 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.

[0033] 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

[0034] Figure 1 This is a three-dimensional perspective view of the shock wave vortex device of the present invention.

[0035] 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).

[0036] 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).

[0037] Figure 4This 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).

[0038] 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).

[0039] 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).

[0040] 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).

[0041] 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).

[0042] 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).

[0043] Figure 10 This is a schematic diagram of the spiral channel in the vaporization chamber of the present invention.

[0044] Explanation of key figure labels:

[0045] 100 - Shockwave vortex device; 101 - Gas inlet for preheating section; 102 - Biomass pellet inlet; 103 - Product gas outlet;

[0046] 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-Gasification chamber, 21-Cylindrical section, 22-Conical section, 23-Feed pipe, 24-Fourth grid blade. Detailed Implementation

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] The inventors discovered that shock wave heating offers unique advantages for heating gases, enabling uniform heating and achieving high temperatures. However, in the biomass hydrogen production process, since the biomass feedstock is a solid particle, if a gas-solid mixture is introduced into the shock wave generator for simultaneous shock wave heating and biomass gasification and pyrolysis, the high gas velocity (nearly supersonic) causes significant impact from the solid particles carried in the gas on the shock wave generator. Specifically, 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 gasification via 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 gasification 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 gasification and pyrolysis efficiency, but also effectively avoids the impact of solid particles and tar droplets on the shock wave generating device.

[0052] like Figures 1 to 5As shown, the present invention provides a shock vortex device 100 for biomass hydrogen production, comprising at least a shock preheating section 1 and a gasification 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 (using steam), 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 gasification chamber 2 includes a cylindrical section 21 and a conical section 22. The shock wave preheating section 1 is tangentially connected to the gasification chamber 2 at the upper part of the cylindrical section 21. Biomass particles and high-temperature gas form a swirling flow in the spiral channel 20 of the cylindrical section 21 and the conical section 22. Gasification occurs in the swirling flow to generate hydrogen-rich synthesis gas (containing hydrogen, methane, and carbon monoxide, etc.), and gas-solid separation occurs in the conical section 22. Preferably, but not limitingly, the spiral channel 20 can be fixed to the inner wall of the gasification chamber 2 and extend downward spirally to partition the swirling gas-solid fluid at different heights, avoiding back-mixing between gas-solid fluids with different gasification degrees.

[0053] In the above-mentioned technical solution of the present invention, by setting a first stator, a rotor, and a second stator in the straight section inside the furnace tube, the process gas (using water vapor) generates a shock wave effect during the operation of the gas channel. It is initially accelerated at the first stator, and the rotation of the rotor accelerates the raw material gas to supersonic speed. 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 with traditional heating methods, this avoids the subsequent product separation problems caused by introducing nitrogen, while also accelerating the heating rate and avoiding the slow heating rate and uneven gas heating problems 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 shock wave heating and biomass pellet gasification process are decoupled, successfully achieving shock wave... This technology, applied to the gas-solid two-phase field, not only avoids the impact of solid particles and tar droplets on the stator and rotor, but also does not affect the subsequent gasification and pyrolysis efficiency. Furthermore, by connecting the shock wave preheating section tangentially to the gasification chamber at the upper part of the cylindrical section, a high-speed, high-temperature gas flow carrying biomass particles swirls downwards along the spiral channel of the gasification chamber. Gasification and pyrolysis occur within this spiral channel, followed by gas-solid separation in the conical section. This avoids back-mixing between gas and solid fluids of different gasification degrees, which would affect the yield of hydrogen-rich gas and the tar content. Simultaneously, the tangential entry into the inner wall of the cylindrical section results in a swirling gas-solid flow with constantly changing direction, periodically altering the velocity difference between gas and solid. This achieves a high-speed, strongly coupled swirling process, providing a large amount of heat for the gasification and pyrolysis of biomass particles in a short time, increasing the rate of volatile release, and thus further improving the yield of hydrogen-rich syngas.

[0054] 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.

[0055] Further as Figures 6 to 9As 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 blade profile parameters of the first blade 131, the second blade 141, and the third blade 151 of the present invention 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).

[0056] Table 1 Leaf type parameters

[0057]

[0058] 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.

[0059] Further as Figure 1As shown, the height-to-diameter ratio of the cylindrical section 21 of the gasification chamber can be set according to the gasification time of the biomass pellets. That is, the height-to-diameter ratio of the cylindrical section determines the number of rotations of the pellets in the gasification chamber, thereby determining the residence time of the biomass pellets in the gasification chamber. The bottom of the conical section 22 of the gasification chamber is provided with a connected feed pipe 23 for discharging or recycling the residual carbon particles after gasification of the biomass pellets. In other words, the feed pipe 23 is used for discharging solid residual carbon particles and collecting them. The collected solid particles can be mixed back into the silo for secondary gasification of particles with incompletely removed volatile matter. Preferably, but not limitingly, the connection between the conical section 22 and the feed pipe 23 is provided with multiple radially extending curved fourth grid blades 24 for further gas-solid separation. That is, the gas channel constructed by the fourth grid blades 24 can be a straight or inclined structure, used to separate the gas-solid mixture from the conical section 22 of the gasification chamber, achieving further gas-solid separation. The top of the gasification chamber 2 is provided with a product gas outlet pipe 103 for discharging the produced hydrogen-rich synthesis gas; a cylindrical metal mesh (not shown in the figure) is provided below the product gas outlet pipe 103 for filtering ash particles and residual carbon particles entrained in the hydrogen-rich synthesis gas.

[0060] refer to Figures 1 to 10 As shown, the present invention also provides a shock wave vortex method for biomass hydrogen production, which, using the above-mentioned apparatus, includes at least the following steps:

[0061] Step S101: Process gas (using water vapor) is introduced into shock wave preheating section 1. After initial acceleration by the first stator 13, the process gas is accelerated to supersonic speed by the rotor 14.

[0062] 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 650-850°C.

[0063] 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 gasification chamber 2 tangentially.

[0064] In step S104, the high-speed gas-solid mixture rotates downwards along the spiral channel 20 inside the gasification chamber 2. Under swirling conditions, the biomass particles are gasified, producing hydrogen-rich syngas (containing hydrogen, methane, and carbon monoxide, etc.) which is discharged into the gas phase through the product gas outlet pipe 103 for further purification. The gas-solid mixture undergoes preliminary gas-solid separation in the conical section 22. It should be noted that the residence time of the biomass particles in the gasification chamber is related to the height-to-diameter ratio of the cylindrical section 21 and the number of rotations of the spiral channel 20. Specifically, the number of turns of the spiral channel, the height-to-diameter ratio of the cylindrical section of the gasification chamber, and the residence time of the biomass particles are related as follows:

[0065]

[0066] Where n is the number of turns in the spiral channel; h is the height of the cylindrical section (m); v is the gas velocity entering the spiral channel (m / s); β is the height-to-diameter ratio of the cylindrical section; t is the residence time of the biomass pellets (s); m is the feed rate of the biomass pellets (kg); and k is the biomass pellet gasification rate (s). -1 .

[0067] The method of the present invention may further include:

[0068] In step S105, the downward rotating fluid after preliminary gas-solid separation undergoes further gas-solid separation via the fourth grid blade 24. Solid residual carbon particles enter the feed pipe 23 and are discharged. If the residual carbon particles are not completely gasified, they can be recycled, meaning that the collected solid particles can be mixed back into the silo to perform secondary gasification on particles that have not been completely depurinated.

[0069] 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" is that the highest temperature of the gas in the shock wave preheating section is about 100-300°C higher than the outlet temperature of conventional tubular furnaces 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 conventional flue gas thermal radiation furnace tubes is higher than the gas temperature inside the 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 tubes. Therefore, when using furnace tubes of the same material, the device of this invention can withstand higher temperatures, providing more heat for the gasification reaction and increasing the yield of hydrogen-rich syngas. Second, "short residence time" refers to a short residence time, which creates conditions for decoupling shock wave heating and biomass gasification, realizing "heating the gas first, and then mixing the gas and solid for biomass particle gasification", without affecting the gasification and cracking efficiency.

[0070] In addition, the method of the present invention carries particles into the gasification chamber through high-speed airflow for cyclone gasification and pyrolysis. When the throughput is large, it solves the problem that conventional devices rely on the gravity of the particles themselves and the rotation speed of the spiral, resulting in slow gas-solid movement and low throughput, which is conducive to 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.

[0071] The effects of the present invention are illustrated below with two specific embodiments:

[0072] Example 1

[0073] refer to Figures 1 to 10Water vapor is added at a water-to-carbon ratio of 1. The 300°C water vapor is initially accelerated at the first stator 13, and then accelerated to supersonic speed by the rotation of the rotor 14. This generates shock wave loss at the second stator 15, instantly raising the temperature of the water vapor to 750-850°C. Simultaneously, biomass pellets (pine waste) enter the end of the shock wave preheating section 1 from above through the feeding screw. The biomass pellets are driven tangentially into the gasification chamber 2 by the water vapor. The high-speed gas-solid fluid rotates downward along the spiral channel 20 inside the gasification chamber, and the spiral channel divides the gas-solid fluid at different heights. To reduce backmixing, due to the shape of the cylinder wall, the velocity difference between the gas and solid fluid changes periodically, and there is relative motion between the gas and solid. The particles are gradually heated, and the high-temperature particles are vaporized in the water vapor atmosphere during rotation, producing hydrogen, methane, and carbon monoxide into the gas phase. The gas and solid fluid gradually separate in the conical section 22, and the particles continue to rotate downward along the pipe wall until they reach the feed pipe 23. The gas then goes through the product gas outlet pipe 103 at the outlet of the gasification chamber for further purification, removing tar and water vapor to obtain hydrogen-rich syngas product with a hydrogen gas fraction of 43.6%.

[0074] Example 2

[0075] refer to Figure 1 Water vapor is added at a water-to-carbon ratio of 1. The 300°C water vapor is initially accelerated at the first stator 13, and then accelerated to supersonic speed by the rotation of the rotor 14. This generates shock wave loss at the second stator 15, instantly raising the temperature of the water vapor to 650-750°C. Simultaneously, biomass pellets (pine waste) and calcium-based catalyst (which can absorb carbon dioxide in situ) are premixed and fed from above into the end of the shock wave preheating section 1 via a feeding screw. The biomass pellets are driven tangentially into the gasification chamber 2 by the water vapor. The high-speed gas-solid fluid rotates downward along the spiral channel 20 inside the gasification chamber. The spiral channel 20 divides the gas-solid fluid at different heights, reducing backmixing. 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, and the high-temperature pellets... The biomass particles are gasified in a steam atmosphere to produce hydrogen, methane, carbon monoxide, and carbon dioxide into the gas phase. The carbon dioxide is captured by the calcium-based catalyst. The gas-solid fluid gradually separates into gas and solid within the conical section 22. The biomass particles continue to rotate downward along the pipe wall until they reach the feed pipe 23. The gas then undergoes further purification through the product gas outlet pipe 103 at the gasification chamber outlet to remove tar and water vapor, resulting in hydrogen-rich syngas product with a hydrogen gas fraction of 65.3%. The downward rotating gas-solid fluid is further separated into gas and solid by the fourth grid leaf 24. The solid particles enter the feed pipe 23 and are discharged from the device of this invention. The discharged residual carbon particles are subjected to flotation. The lighter residual carbon and ash particles are discharged, while the heavier catalyst is calcined and regenerated to remove carbon dioxide before being re-entered into the silo to be premixed with fresh raw materials.

[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 shockwave vortex device for biomass hydrogen production, 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 gasification chamber includes a cylindrical section and a conical section. The shock wave preheating section is tangentially connected to the gasification chamber at the upper part of the cylindrical section. Biomass particles and high-temperature gas form a swirling flow in the spiral channels of the cylindrical and conical sections. Gasification is carried out in the swirling flow state to generate hydrogen-rich synthesis gas, and gas-solid separation is carried out in the conical section.

2. The shockwave vortex device for biomass hydrogen production 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 shockwave vortex device for biomass hydrogen production 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 shockwave vortex device for biomass hydrogen production 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 shockwave vortex device for biomass hydrogen production 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 shockwave vortex device for biomass hydrogen production according to claim 1, characterized in that, The height-to-diameter ratio of the cylindrical section of the gasification chamber is set according to the gasification time of the biomass pellets. The number of rotations of the pellets in the gasification chamber is determined by setting the height-to-diameter ratio of the cylindrical section, thereby determining the residence time of the biomass pellets in the gasification chamber.

7. The shockwave vortex device for biomass hydrogen production according to claim 1, characterized in that, The bottom of the conical section of the gasification chamber is equipped with a feed pipe for discharging or recycling the residual carbon particles after biomass pellet gasification.

8. The shockwave vortex device for biomass hydrogen production 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 shockwave vortex device for biomass hydrogen production according to claim 1, characterized in that, The spiral channel is fixed to the inner wall of the vaporization chamber and extends downwards in a spiral pattern. It is used to divide the swirling gas-solid fluid at different heights into zones to avoid back mixing between gas-solid fluids with different vaporization degrees.

10. The shockwave vortex device for biomass hydrogen production according to claim 1, characterized in that, The top of the gasification chamber is equipped with a product gas outlet pipe for discharging the produced hydrogen-rich synthesis gas; a cylindrical metal mesh is provided below the product gas outlet pipe for filtering ash particles and residual carbon particles entrained in the product gas.

11. A shock vortex method for biomass hydrogen production, 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. 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 flow carrying the pellets enters the gasification chamber tangentially. D. The high-speed gas-solid mixture rotates downward along the spiral channel set in the gasification chamber. The biomass particles are gasified in the swirling state, and the produced hydrogen-rich synthesis gas is discharged into the gas phase through the product gas outlet pipe for the next step of purification. The gas-solid mixture undergoes preliminary gas-solid separation in the conical section.

12. The shock vortex method for biomass hydrogen production 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. In cases where residual carbon particles are not completely gasified, cyclic gasification is performed.

13. The shock vortex method for biomass hydrogen production according to claim 11, characterized in that, The process gas is water vapor; the hydrogen-rich synthesis gas contains hydrogen, methane, and carbon monoxide.

14. The shock vortex method for biomass hydrogen production according to claim 11, characterized in that, The number of turns in the spiral channel, the aspect ratio of the cylindrical section of the gasification chamber, and the residence time of the biomass pellets are related as follows: Where n is the number of turns in the spiral channel; h is the height of the cylindrical section (m); v is the gas velocity entering the spiral channel (m / s); β is the height-to-diameter ratio of the cylindrical section; t is the residence time of the biomass pellets (s); m is the feed rate of the biomass pellets (kg); and k is the biomass pellet gasification rate (s). -1 .

15. The shock vortex method for biomass hydrogen production according to claim 11, characterized in that, In step B, the temperature of the process gas is rapidly raised to 650-850°C.

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