Organic solid waste gasification system, organic solid waste gasification method and application

Abstract

The invention provides an organic solid waste gasification system, an organic solid waste gasification method and application. The organic solid waste gasification system comprises a feeding device; the gasification reaction device is used for carrying out primary gasification on the organic solid waste conveyed by the feeding device to obtain primary crude synthesis gas; the high-temperature conversion device is connected with the gasification reaction device and is used for carrying out secondary gasification on the crude synthesis gas conveyed by the gasification reaction device in a rotational flow field to realize methane reforming, tar cracking, deep conversion of plastic cracking products and ash agglomeration so as to obtain secondary crude synthesis gas; and the purification device is connected with the high-temperature conversion device and is used for purifying the secondary crude synthesis gas conveyed by the high-temperature conversion device to obtain purified synthesis gas. Through organic coupling of the gasification reaction device and the high-temperature conversion device, the gasification efficiency is improved, methane reforming and tar cracking are realized, the quality of synthesis gas is remarkably improved, and long-term stable operation of the system is guaranteed.

Description

Technical Field

[0001] This invention belongs to the field of organic solid waste utilization technology, specifically relating to an organic solid waste gasification system, an organic solid waste gasification method, and its application. Background Technology

[0002] Organic solid waste (hereinafter referred to as "organic solid waste") refers to solid or semi-solid waste materials containing natural or synthetic organic compounds generated in human social production and life activities. Typical examples include biomass, waste plastics, and waste tires. These materials are characterized by high carbon and hydrogen content and great resource potential. If not disposed of properly, they will cause environmental pollution and waste of resources.

[0003] Organic solid waste gasification, as a thermochemical conversion technology, can transform waste into high-value-added energy products. For example, biomass gasification can convert renewable raw materials such as crop straw, forestry waste, livestock and poultry manure, and urban organic waste into syngas, which is mainly composed of carbon monoxide (CO) and hydrogen (H2). This technology can not only alleviate the shortage of fossil fuels but also reduce greenhouse gas emissions, showing broad prospects in the field of green energy and clean fuel production.

[0004] However, the most common biomass gasification furnace types at present include fixed-bed gasifiers (updraft and downdraft), bubbling / circulating fluidized bed gasifiers, and entrained flow gasifiers. Fixed-bed gasifiers are widely used due to their simple structure, mature technology, and low investment, but they have a smaller processing capacity, are prone to slagging on the grate, have high tar content, and low gasification efficiency. Bubbling / circulating fluidized bed gasifiers have strong feedstock adaptability and are easy to scale up, but their gasification temperature is limited, resulting in high impurity content in the fuel gas, large tar production, and high fly ash production. Entrained flow gasifiers have high reaction temperatures (above 1200℃) and produce gas with almost no tar, but they require extremely fine feedstock particles (usually 300μm), and the biomass particles need to be pretreated by baking or pyrolysis, resulting in high energy consumption and high equipment investment.

[0005] Currently, the biggest challenge in biomass gasification in industrial applications lies in the difficulty of completely cracking tar. This tar, once downstream, easily causes coking in equipment and blockage in pipelines, leading to excessive burden on downstream purification systems and high operating costs. The low melting point of ash slag makes it prone to slagging, agglomeration, or adhesion to the walls, disrupting the fluidization state of the bed and affecting the continuous and stable operation of the system. High-temperature tar and fly ash also easily adhere to the furnace inner wall, reducing heat transfer efficiency, increasing cleaning and maintenance costs, and severely affecting the fluidization state and reaction stability. Existing systems lack sufficient capacity for deep tar conversion and have limited control over syngas composition, resulting in poor syngas quality with low CO and H2 concentrations, making it difficult to meet the needs of subsequent synthetic fuels or chemical synthesis (such as methanol, DME, and hydrogen extraction).

[0006] Researchers have proposed numerous improvement methods. For example, patent CN216404311U designs a low-tar biomass gasification system. The structural design of the tar pyrolyzer and the utilization of waste heat can reduce the tar content in the gasification products and improve the purity of the fuel gas to a certain extent. However, its shortcomings include limited pyrolysis temperature, easy catalyst deactivation, insufficient syngas quality control, and inadequate consideration of ash treatment, which still limits its industrial application. Patent CN120505126A proposes a syngas preparation method based on a dual-cycle gasifier. By combining dual-cycle gasification with tar pyrolysis, it effectively improves the syngas quality and carbon conversion efficiency, overcoming the problems of low carbon conversion rate and gasification efficiency, and insufficient CO and H2 content in the syngas during traditional biomass gasification. However, it still faces limitations such as low gasification temperature, system complexity, insufficient catalyst stability, high-temperature tar pyrolysis energy consumption, and insufficient ash treatment. Patent CN112694918A designs a composite gasification system of pressurized fluidized bed gasification and cyclone pyrolysis for biomass. Through a composite design of pressurized fluidized bed + high-temperature cyclone pyrolysis + multi-stage return and dust removal, it significantly improves biomass gasification efficiency and reduces tar content. However, it still suffers from limitations such as system complexity, high energy consumption, easy catalyst deactivation, and imperfect ash treatment, affecting the stability and economics of industrial applications. Patent CN120519198A proposes a biomass gasification system and fluidized bed gasification process. Through bed material pre-addition, circulating return, and high-pressure fluidized bed technology, it innovatively solves the slagging problem and reduces tar content, improving syngas quality and plant stability. However, it still has shortcomings in deep tar conversion, continuous ash discharge, and precise control of syngas composition, limiting further industrial application. Patent CN118546706A proposes a system and method for producing low-tar, low-methane syngas from biomass gasification. Through a combination of pressurized pure oxygen gasification, high-temperature conversion pyrolysis, and circulating quench dust removal, it significantly reduces tar and methane content while improving energy efficiency and system reliability. However, it still suffers from limitations such as system complexity, high energy consumption, insufficient complete tar conversion and ash treatment, and limited gas composition control capabilities, hindering its further industrial promotion and optimization. Patent CN119752488A designs a method and system for clean biomass gasification. By utilizing native moisture in the raw material to replace external steam, recycling energy, and staged tar pyrolysis, it significantly improves gasification efficiency and fuel quality while reducing system operating costs. However, it still suffers from limitations such as insufficient deep tar conversion, weak ash treatment, system complexity, and limited syngas composition control capabilities, affecting the stability and applicability of large-scale promotion.Patent CN120209891A proposes a system and method for producing syngas by coupling biomass dual-fluidized bed chemical looping gasification with oxygen-enriched combustion. Through this coupling, high-quality syngas and high-concentration O2 are co-produced, improving carbon conversion rate and energy efficiency. However, it still suffers from limitations such as system complexity, insufficient oxygen carrier stability, weak ash treatment, and limited economic viability, requiring further optimization for industrial application. Patent CN117089373A designs a pulverized coal composite riser staged pyrolysis gasification process for producing fuel gas. Through a multi-stage process of composite riser staged pyrolysis + stepped turbulent bed + high-temperature gas flow bed melting gasification, it achieves the preparation of high-methane, low-tar fuel gas and a reduction in residual carbon content, significantly improving gasification efficiency and stability. However, it still suffers from limitations such as process complexity, high energy consumption, reliance on returned particles for ash treatment, insufficient syngas composition control, and limited applicability, restricting its wider application and promotion under various fuel conditions.

[0007] Therefore, how to achieve efficient pyrolysis of tar and stable discharge of ash while ensuring gasification efficiency is a core problem that urgently needs to be solved in this field. Summary of the Invention

[0008] To address the shortcomings of existing technologies, the present invention aims to provide an organic solid waste gasification system, a gasification method for organic solid waste, and its applications. This invention organically couples the gasification reactor with a high-temperature conversion device, making the gasification process more efficient and overcoming the limitations of a single reactor in terms of temperature distribution and reaction mechanism. It not only enables methane reforming and tar cracking, reducing the tar and methane content in syngas and significantly increasing CO and H2 concentrations, but also improves carbon conversion rate and gasification efficiency. More importantly, the swirling flow field prevents tar and ash particles from adhering to the inner wall of the device, enabling automatic settling and centralized discharge of ash, ultimately significantly improving syngas quality, ensuring the long-term stability of the system, and providing a more efficient and cleaner gas source for downstream syngas utilization.

[0009] To achieve this objective, the present invention adopts the following technical solution:

[0010] In a first aspect, the present invention provides an organic solid waste gasification system, the organic solid waste gasification system comprising:

[0011] Feeding device.

[0012] A gasification reactor is used to gasify the organic solid waste conveyed by the feeding device to obtain primary crude syngas.

[0013] A high-temperature conversion device is connected to the gasification reaction device and is used to perform secondary gasification of the crude syngas transported by the gasification reaction device in a swirling flow field to achieve tar reforming, methane cracking and ash agglomeration to obtain secondary crude syngas.

[0014] A purification device is connected to the high-temperature conversion device and is used to purify the secondary crude syngas supplied by the high-temperature conversion device to obtain purified syngas.

[0015] This invention organically couples the gasification reactor with the high-temperature conversion unit to form a series structure, making the gasification process more efficient. It overcomes the limitations of a single reactor in terms of temperature distribution and reaction mechanism. It can not only achieve methane reforming and tar cracking, reducing the tar and methane content in syngas and significantly increasing CO and H2 concentrations, but also improve carbon conversion rate and gasification efficiency. More importantly, the swirling flow field can prevent tar and ash particles from adhering to the inner wall of the unit, realizing automatic settling and centralized discharge of ash, ultimately significantly improving the quality of syngas, ensuring the long-term stability of the system, and providing a more efficient and cleaner gas source for downstream syngas utilization.

[0016] In this invention, the gasification reactor is responsible for the initial gasification and pyrolysis reaction to generate crude syngas and carbon-containing fly ash, while the high-temperature conversion unit performs methane reforming and tar cracking, which significantly reduces the tar and methane content and significantly increases the proportion of effective components in the syngas. The coupling of the two makes the gasification process more efficient, overcomes the limitations of a single reactor in terms of temperature distribution and reaction mechanism, and significantly reduces the subsequent purification and compression load.

[0017] This invention utilizes a gasification reaction device and a high-temperature conversion device to achieve ash agglomeration and efficient discharge, avoiding bed slagging and gasification channel blockage problems, and improving the stability and continuity of system operation.

[0018] This invention employs a waste heat recovery design. The gasifying agent used in the secondary gasification process is preheated by the temperature of the heating jacket outside the high-temperature conversion unit before entering, significantly reducing the energy requirement for an additional heat source and minimizing external energy consumption. The produced gas has high cleanliness, and pollutant emissions are significantly reduced, aligning with the trend of green energy development. Preferably, the feeding device is a screw feeder.

[0019] In this invention, organic solid waste particles are sealed and fed into the gasification reaction device through a screw feeder. The screw feeder can maintain stable pressure inside the gasification reaction device while preventing raw material backflow and air leakage.

[0020] Preferably, the gasification reaction device is selected from any one of a low-temperature sputtering bed gasifier, a bubbling fluidized bed, or a circulating fluidized bed, and is preferably a low-temperature sputtering bed gasifier.

[0021] The reason why the present invention prefers a low-temperature sputtering bed gasifier is that bubbling fluidized beds and circulating fluidized beds generate a large amount of tar during the gasification process, which is difficult to completely convert, and are prone to slagging under high temperature conditions, thus clogging the gasifier.

[0022] Preferably, the inner cavity of the low-temperature sputtering bed gasifier is divided into an upper chamber and a lower chamber. The lower chamber of the low-temperature sputtering bed gasifier is connected to the feeding device, and the upper chamber of the low-temperature sputtering bed gasifier is connected to the high-temperature conversion device through a pipeline.

[0023] Preferably, the bottom of the low-temperature sputtering bed gasifier has a downwardly narrowing structure, and a channel is provided at the axis of the downwardly narrowing structure. The end of the channel is provided with a primary gasifying agent inlet and a slag discharge port. The primary gasifying agent inlet is used to inject and introduce the primary gasifying agent, so that the biomass pellets generate the primary crude syngas. The slag discharge port is used to discharge large particles of inert ash.

[0024] In this invention, the primary gasifying agent is injected through the primary gasifying agent inlet, which helps to form a jet-fluidized state, so that the biomass particles can be heated rapidly, undergo pyrolysis and partial gasification reactions, and generate crude syngas containing tar, methane and some ash.

[0025] It should be noted that large-particle inert ash is an inert inorganic residue formed during the gasification process of organic solid waste (such as biomass). It has a large particle size, is difficult to further participate in the gasification reaction, and remains essentially solid at high temperatures. Its main components typically include inert inorganic substances such as K₂O, Na₂O, SiO₂, Al₂O₃, CaO, MgO, and metal oxides. Due to its high density and fast settling velocity, this type of ash preferentially accumulates at the bottom of the low-temperature sputtered bed gasifier. It can be stably discharged through the bottom ash discharge port, preventing its accumulation inside the furnace and affecting the fluidization state and reaction efficiency.

[0026] Preferably, the high-temperature conversion device is selected from any one of a cylindrical high-temperature conversion furnace, a vertical fluidized bed furnace, or a double-layer furnace.

[0027] It should be noted that the vertical fluidized bed utilizes high-speed injection of gasifying agent to create turbulence and a high-temperature zone, completing tar cracking and ash settling. In the double-layer furnace, the upper part is the high-temperature cracking zone, and the lower part is the ash settling chamber. Compared to the cylindrical high-temperature converter, these two types of high-temperature conversion devices require a larger investment, struggle to create a stable swirling field inside, and the tar easily condenses and cokes on the furnace wall. The ash lacks sufficient centrifugal force, hindering effective agglomeration and settling, resulting in poor system stability.

[0028] Preferably, the inner wall of the cylindrical high-temperature converter is provided with at least one tangential nozzle group along the circumferential direction for injecting secondary gasifying agent to form the swirling flow field. For example, at least one nozzle group can be one, two, three, or four nozzle groups.

[0029] This invention designs a tangential nozzle group along the circumferential direction on the inner wall of a cylindrical high-temperature converter to inject a secondary gasifying agent and form a swirling flow field. It has the following advantages: 1) It makes the gas and solid mixture uniform and enhances the cracking and reforming reaction of tar; 2) The swirling shear and high temperature cause fine ash particles to collide, adhere and agglomerate, eventually forming larger ash particles. Under the action of gravity, these particles settle to the bottom of the furnace and are discharged, avoiding the problems of bed slagging and gasification channel blockage, and improving the stability and continuity of system operation; 3) The swirling air curtain can effectively prevent the deposition and adhesion of tar and fly ash on the furnace wall, ensuring the cleanliness of the inner wall, improving heat transfer efficiency, and helping to extend the service life of the equipment.

[0030] This invention involves injecting a primary gasifying agent into the bottom of a low-temperature sputtering bed gasifier and injecting a secondary gasifying agent into a cylindrical high-temperature converter through a tangential nozzle group to form a swirling flow field. The two processes are controlled independently, effectively ensuring the optimal operating conditions of the gasifier and the converter.

[0031] Preferably, the tangential nozzle assembly includes at least one tangential nozzle along the axial direction of the cylindrical high-temperature converter. For example, at least one may be one, two, three, or four, etc.

[0032] Preferably, the top of the cylindrical high-temperature converter is provided with an air inlet for introducing a gasifying agent.

[0033] Preferably, the bottom of the cylindrical high-temperature converter is provided with a slag collection hopper, and a slag collection cavity is formed between the side wall of the slag collection hopper and the inner wall of the cylindrical high-temperature converter for collecting ash and slag generated during the secondary gasification process.

[0034] In this invention, the above design facilitates the centralized separation and smooth discharge of ash and slag. Furthermore, the top air inlet provides a stable source of supplemental gasifying agent, which helps maintain the heat balance in the high-temperature conversion zone, while the bottom slag collection hopper prevents ash and slag from accumulating in the high-temperature zone and prevents blockage, thereby ensuring the long-term, stable, and efficient operation of the high-temperature converter.

[0035] Preferably, the bottom of the slag collection chamber is provided with a slag discharge port for discharging the ash and slag collected in the slag collection chamber.

[0036] Preferably, the side wall of the high-temperature converter is provided with a syngas outlet, which is connected to the slag collection chamber to discharge the secondary crude syngas collected above the ash slag in the slag collection chamber.

[0037] Preferably, the syngas outlet is connected to the air inlet of the purification device via a pipeline.

[0038] Preferably, the purification device includes a dust removal unit, a cooling unit, a washing unit, and a drying unit along the direction of gas movement.

[0039] In a second aspect, the present invention provides a gasification method for organic solid waste, the gasification method using the organic solid waste gasification system as described in the first aspect, comprising the following steps:

[0040] Organic solid waste is fed to a gasification reactor via a feeding device, where it undergoes a primary gasification process to generate primary crude syngas.

[0041] The primary crude syngas is transported to a high-temperature conversion unit, where it undergoes secondary gasification in a swirling flow field to achieve methane reforming, tar cracking, and ash agglomeration, generating secondary crude syngas.

[0042] The secondary crude syngas is transported to a purification device for purification to obtain purified syngas.

[0043] Preferably, the organic solid waste includes any one or a combination of at least two of biomass waste, waste plastics, or waste tires. It should be noted that the source of the biomass raw materials is not limited; for example, it can be straw, rice husks, sawdust, and manure.

[0044] Preferably, the particle size D50 of the biomass waste is 0.5-6mm, for example, it can be 0.5mm, 1mm, 2mm, 3mm, 4mm, 5mm or 6mm, etc.

[0045] Preferably, the primary vaporizing agent introduced into the vaporization reaction device includes any one or a combination of at least two of air, oxygen, or water vapor.

[0046] Preferably, during the primary gasification process, the operating temperature of the gasification reaction device is 700-900℃, for example, 700℃, 800℃ or 900℃.

[0047] Preferably, the primary crude syngas contains tar, methane, and ash.

[0048] Preferably, the secondary gasifying agent introduced into the high-temperature conversion device includes any one or a combination of at least two of air, oxygen, or water vapor.

[0049] Preferably, during the secondary gasification process, the operating temperature of the high-temperature conversion device is 950-1200℃, for example, it can be 950℃, 1000℃, 1050℃, 1100℃, 1150℃ or 1200℃, etc.

[0050] In the secondary gasification process, this invention achieves deep conversion of tar and methane by using a specific operating temperature of the high-temperature conversion device in combination with a specific secondary gasification agent, which significantly increases the concentration of CO and H2 in the syngas and reduces the content of tar and methane.

[0051] Preferably, the secondary crude syngas contains CO and H2, wherein the volume concentration of CO is 20-30 vol%, for example, 20 vol%, 25 vol%, or 30 vol%, and the volume concentration of H2 is 40-60 vol%, for example, 40 vol%, 50 vol%, or 60 vol%.

[0052] Preferably, the purified syngas, by volume fraction, comprises:

[0053] 25-35 vol% (e.g., 25 vol%, 30 vol%, or 35 vol%) of CO, 45-60 vol% (e.g., 45 vol%, 50 vol%, 55 vol%, or 60 vol%) of H2, <5 vol% of methane (e.g., 4 vol%, 3 vol%, 2 vol%, or 1 vol%), and <3 vol% of tar (e.g., 2.5 vol%, 2 vol%, or 1 vol%).

[0054] Thirdly, the present invention provides an application of purified syngas obtained by the gasification method described in the second aspect in the fuel field or chemical synthesis field.

[0055] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0056] Compared with the prior art, the present invention has the following beneficial effects:

[0057] This invention organically couples the gasification reactor with a high-temperature conversion unit, making the gasification process more efficient. It overcomes the limitations of a single reactor in terms of temperature distribution and reaction mechanism. It can not only achieve methane reforming and tar cracking, reducing the tar and methane content in syngas and significantly increasing CO and H2 concentrations, but also improve carbon conversion rate and gasification efficiency. More importantly, the swirling flow field can prevent tar and ash particles from adhering to the inner wall of the unit, enabling automatic settling and centralized discharge of ash, ultimately significantly improving the quality of syngas, ensuring the long-term stability of the system, and providing a more efficient and cleaner gas source for downstream syngas utilization. Attached Figure Description

[0058] Figure 1This is a schematic diagram of the structure of an organic solid waste gasification system provided in a specific embodiment of the present invention.

[0059] Figure 2 This is a schematic diagram of a tangential nozzle assembly provided in a specific embodiment of the present invention.

[0060] Among them, 1-screw feeder; 2-low temperature jetting bed gasifier; 3-cylindrical high temperature converter; 4-purification device; 5-ash and slag pool; 6-top air inlet; 7-pressure relief device; 8-slag discharge machine. Detailed Implementation

[0061] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0062] It should be understood that in the description of this invention, the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0063] It should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "set," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0064] It should be noted that the following example uses biomass waste as organic solid waste.

[0065] In one specific embodiment, the present invention provides a biomass gasification system, the structural schematic diagram of which is shown below. Figure 1 As shown, the biomass gasification system includes:

[0066] Screw feeder 1.

[0067] The low-temperature sputtering bed gasifier 2 is used to perform primary gasification of the biomass conveyed by the screw feeder 1 to obtain primary crude syngas.

[0068] A cylindrical high-temperature converter 3 is connected to the low-temperature sputtering bed gasifier 2. It is used to perform secondary gasification of the crude syngas transported by the low-temperature sputtering bed gasifier 2 in a swirling flow field to achieve tar reforming, methane cracking and ash agglomeration to obtain secondary crude syngas.

[0069] Purification device 4 is connected to the cylindrical high-temperature converter 3 and is used to purify the secondary crude syngas transported by the cylindrical high-temperature converter 3 to obtain purified syngas.

[0070] Furthermore, the inner cavity of the low-temperature sputtering bed gasifier 2 is divided into an upper chamber and a lower chamber. The lower chamber of the low-temperature sputtering bed gasifier 2 is connected to the screw feeder 1, and the upper chamber of the low-temperature sputtering bed gasifier 2 is connected to the cylindrical high-temperature converter 3 through a pipeline.

[0071] Furthermore, the bottom of the low-temperature sputtering bed gasifier 2 has a downwardly narrowing structure, and a channel is provided at the axis of the downwardly narrowing structure. The end of the channel is provided with a primary gasifying agent inlet and a slag discharge port. The primary gasifying agent inlet is used to inject and introduce the primary gasifying agent, so that the biomass pellets generate the primary crude syngas. The slag discharge port is used to discharge large particles of inert ash.

[0072] Furthermore, a slag discharge machine 8 is externally connected to the slag discharge port to drive and control the continuous and stable discharge of large-particle inert ash slag.

[0073] Furthermore, a pressure relief device 7 is provided on the top of the cryogenic jet-driven gasifier 2.

[0074] Furthermore, the pressure relief device 7 includes a safety valve and a pressure relief valve. Furthermore, the inner wall of the cylindrical high-temperature converter 3 is provided with at least one tangential nozzle group along the circumferential direction for injecting secondary gasifying agent to form a swirling flow field. For example... Figure 2 As shown, one, two, or four tangential nozzle groups can be installed along the circumferential direction on the inner wall of the cylindrical high-temperature converter 3.

[0075] Furthermore, the tangential nozzle group includes three tangential nozzles along the axial direction of the cylindrical high-temperature converter 3.

[0076] Furthermore, the top of the cylindrical high-temperature converter 3 is provided with a top air inlet 6 for introducing a gasifying agent. For example, the gasifying agent may be water vapor or oxygen.

[0077] Furthermore, the bottom of the cylindrical high-temperature converter 3 is provided with a slag collection hopper, and a slag collection cavity is formed between the side wall of the slag collection hopper and the inner wall of the cylindrical high-temperature converter 3 for collecting ash and slag generated during the secondary gasification process.

[0078] Furthermore, a slag discharge port is provided at the bottom of the slag collection chamber for discharging the ash and slag collected in the slag collection chamber.

[0079] Furthermore, the side wall of the high-temperature converter is provided with a syngas outlet, which is connected to the slag collection chamber and is used to discharge the secondary crude syngas above the ash and slag collected in the slag collection chamber.

[0080] Furthermore, the syngas outlet is connected to the air inlet of the purification device 4 via a pipeline.

[0081] Furthermore, the ash discharged from the slag outlet of the high-temperature converter is collected in the ash pool 5.

[0082] Furthermore, the purification device 4 includes a dust removal unit, a cooling unit, a washing unit, and a drying unit along the direction of gas movement.

[0083] In another embodiment, the present invention provides a method for gasifying biomass waste, the gasification method using the biomass gasification system described above, comprising the following steps:

[0084] (1) Biomass waste is conveyed to a low-temperature sputtering bed gasifier via a screw feeder and undergoes primary gasification in the low-temperature sputtering bed gasifier to generate primary crude syngas; wherein the particle size D50 of the biomass waste is 0.5-6 mm; the primary gasification agent introduced into the low-temperature sputtering bed gasifier includes any one or a combination of at least two of air, oxygen or water vapor; during the primary gasification process, the operating temperature of the low-temperature sputtering bed gasifier is 700-900℃; the primary crude syngas contains tar, methane and ash.

[0085] (2) The primary crude syngas is transported to a cylindrical high-temperature converter for secondary gasification to achieve tar reforming, methane cracking and ash agglomeration, generating secondary crude syngas; wherein, the secondary gasification agent introduced into the cylindrical high-temperature converter includes any one or at least two of air, oxygen or water vapor; during the secondary gasification process, the operating temperature of the cylindrical high-temperature converter is 950-1200℃; the secondary crude syngas contains CO and H2, wherein the volume concentration of CO is 20-30 vol%, and the volume concentration of H2 is 40-60 vol%.

[0086] (3) The secondary crude syngas is transported to a purification device for purification to obtain purified syngas; wherein the purified syngas, by volume fraction, includes: 25-35 vol% CO, 45-60 vol% H2, methane < 5 vol%, and tar < 3 vol%.

[0087] Example 1

[0088] This embodiment provides a gasification method for biomass waste. The gasification method uses the biomass gasification system described above and includes the following steps:

[0089] (1) Biomass waste is transported to a low-temperature sputtering bed gasifier via a screw feeder and undergoes primary gasification in the low-temperature sputtering bed gasifier to generate primary crude syngas; wherein, the biomass waste is straw with a particle size D50 of 3 mm; the primary gasification agent introduced into the low-temperature sputtering bed gasifier is water vapor; during the primary gasification process, the operating temperature of the low-temperature sputtering bed gasifier is 800℃; the primary crude syngas contains tar, methane and ash.

[0090] (2) The primary crude syngas is transported to a cylindrical high-temperature converter for secondary gasification to achieve tar reforming, methane cracking and ash agglomeration, generating secondary crude syngas; wherein, the secondary gasification agent introduced into the cylindrical high-temperature converter is water vapor; during the secondary gasification process, the operating temperature of the cylindrical high-temperature converter is 1050℃; the secondary crude syngas contains CO and H2, wherein the volume concentration of CO is 25 ol% and the volume concentration of H2 is 50 vol%.

[0091] (3) The secondary crude syngas is transported to a purification device for purification to obtain purified syngas; wherein the purified syngas, by volume fraction, includes: 30 vol% CO, 55 vol% H2, <5 vol% methane, and <3 vol% tar.

[0092] Example 2

[0093] The difference between this embodiment and Embodiment 1 is that the cylindrical high-temperature conversion furnace does not have a tangential nozzle assembly.

[0094] The remaining gasification methods, parameters, and apparatus are consistent with those in Example 1.

[0095] Comparative Example 1

[0096] The difference between this comparative example and Example 1 is that the biomass gasification system used in the gasification method does not include a low-temperature sputtering bed gasifier.

[0097] The remaining gasification methods, parameters, and apparatus are consistent with those in Example 1.

[0098] Comparative Example 2

[0099] The difference between this comparative example and Example 1 is that the biomass gasification system used in the gasification method does not include a cylindrical high-temperature converter.

[0100] The remaining gasification methods, parameters, and apparatus are consistent with those in Example 1.

[0101] As can be seen from the comparison between Example 1 and Example 2, if the cylindrical high-temperature conversion furnace is not equipped with a tangential nozzle group, the ash will be dispersed in the furnace and will easily adhere to the furnace wall, making it difficult to achieve effective agglomeration and smooth discharge.

[0102] As can be seen from the comparison of Examples 1 and 2 in Example 1, if only a single cylindrical high-temperature converter or a low-temperature sputtering bed gasifier is used, it is not possible to simultaneously and effectively solve the problems of high tar content and ash agglomeration and emission during the gasification process.

[0103] In summary, this method organically couples the gasification reactor with the high-temperature conversion unit, making the gasification process more efficient and overcoming the limitations of a single reactor in terms of temperature distribution and reaction mechanism. It can not only achieve methane reforming and tar cracking, reducing the tar and methane content in syngas and significantly increasing CO and H2 concentrations, but also improve carbon conversion rate and gasification efficiency, promote ash agglomeration and smooth discharge, and ultimately significantly improve syngas quality, ensuring the long-term stability of the system and providing a more efficient and cleaner gas source for downstream syngas utilization. Furthermore, this invention designs a tangential nozzle group along the circumferential direction on the inner wall of the cylindrical high-temperature converter to inject a secondary gasifying agent to form a swirling flow field, which has the following advantages: 1) It makes the gas-solid mixture uniform and strengthens the cracking and reforming reaction of tar; 2) The swirling shear and high temperature cause fine ash particles to collide, adhere and agglomerate, eventually forming larger ash particles, which settle to the bottom of the furnace and are discharged under gravity, avoiding the problems of bed slagging and gasification channel blockage, and improving the stability and continuity of system operation; 3) The swirling air curtain can effectively prevent the deposition and adhesion of tar and fly ash on the furnace wall, ensuring the cleanliness of the inner wall, improving heat transfer efficiency, and helping to extend the service life of the equipment.

[0104] It should be noted that the present invention is illustrated through the above embodiments, but the present invention is not limited to the above process steps, that is, it does not mean that the present invention must rely on the above process steps to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials used in the present invention, additions of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. An organic solid waste gasification system, characterized in that, The organic solid waste gasification system includes: Feeding device; A gasification reactor is used to gasify the organic solid waste conveyed by the feeding device to obtain primary crude syngas. A high-temperature conversion device is connected to the gasification reaction device and is used to perform secondary gasification of the crude syngas transported by the gasification reaction device in a swirling flow field to achieve methane reforming, tar cracking and ash agglomeration to obtain secondary crude syngas. A purification device is connected to the high-temperature conversion device and is used to purify the secondary crude syngas supplied by the high-temperature conversion device to obtain purified syngas.

2. The organic solid waste gasification system according to claim 1, characterized in that, The feeding device is a screw feeder; Preferably, the gasification reaction device is selected from any one of a cryogenic sputtering bed gasifier, a bubbling fluidized bed, or a circulating fluidized bed; Preferably, the inner cavity of the low-temperature sputtering bed gasifier is divided into an upper chamber and a lower chamber. The lower chamber of the low-temperature sputtering bed gasifier is connected to the feeding device, and the upper chamber of the low-temperature sputtering bed gasifier is connected to the high-temperature conversion device through a pipeline. Preferably, the bottom of the low-temperature sputtering bed gasifier has a downwardly narrowing structure, and a channel is provided at the axis of the downwardly narrowing structure. The end of the channel is provided with a primary gasifying agent inlet and a slag discharge port. The primary gasifying agent inlet is used to inject and introduce the primary gasifying agent, so that the organic solid waste particles generate the primary crude syngas. The slag discharge port is used to discharge large particles of inert ash.

3. The organic solid waste gasification system according to claim 1 or 2, characterized in that, The high-temperature conversion device is selected from any one of a cylindrical high-temperature conversion furnace, a vertical fluidized bed furnace, or a double-layer furnace; Preferably, the inner wall of the cylindrical high-temperature converter is provided with at least one tangential nozzle group along the circumferential direction for injecting secondary gasifying agent to form the swirling flow field; Preferably, the tangential nozzle assembly includes at least one tangential nozzle along the axial direction of the cylindrical high-temperature converter.

4. The organic solid waste gasification system according to claim 3, characterized in that, The top of the cylindrical high-temperature converter is provided with an air inlet for introducing gasifying agent; Preferably, the bottom of the cylindrical high-temperature converter is provided with a slag collection hopper, and a slag collection cavity is formed between the side wall of the slag collection hopper and the inner wall of the cylindrical high-temperature converter for collecting ash and slag generated during the secondary gasification process. The bottom of the slag collection chamber is provided with a slag discharge port for discharging the ash and slag collected in the slag collection chamber.

5. The organic solid waste gasification system according to claim 4, characterized in that, The cylindrical high-temperature converter has a syngas outlet on its side wall, which is connected to the slag collection chamber to discharge the secondary crude syngas above the ash and slag collected in the slag collection chamber. The syngas outlet is connected to the air inlet of the purification device via a pipeline; Preferably, the purification device includes a dust removal unit, a cooling unit, a washing unit, and a drying unit along the direction of gas movement.

6. A gasification method for organic solid waste, characterized in that, The gasification method uses the organic solid waste gasification system as described in any one of claims 1-5, and includes the following steps: Organic solid waste is fed to a gasification reactor via a feeding device, where it undergoes a primary gasification process to generate primary crude syngas. The primary crude syngas is transported to a high-temperature conversion unit, where it undergoes secondary gasification in a swirling flow field to achieve methane reforming, tar cracking, and ash agglomeration, generating secondary crude syngas. The secondary crude syngas is transported to a purification device for purification to obtain purified syngas.

7. The gasification method according to claim 6, characterized in that, The organic solid waste includes any one or a combination of at least two of the following: biomass waste, waste plastics, or waste tires. Preferably, the primary gasifying agent introduced into the gasification reaction device includes any one or a combination of at least two of air, oxygen, or water vapor; Preferably, during the primary gasification process, the operating temperature of the gasification reaction device is 700-900℃; Preferably, the primary crude syngas contains tar, methane, and ash.

8. The gasification method according to claim 6 or 7, characterized in that, The secondary gasifying agent introduced into the high-temperature conversion device includes any one or a combination of at least two of air, oxygen, or water vapor. Preferably, during the secondary gasification process, the operating temperature of the high-temperature conversion device is 950-1200℃; Preferably, the secondary crude syngas contains CO and H2, wherein the volume concentration of CO is 20-30 vol% and the volume concentration of H2 is 40-60 vol%.

9. The gasification method according to any one of claims 6-8, characterized in that, The purified synthesis gas, by volume fraction, comprises: 25-35 vol% CO, 45-60 vol% H2, methane <5 vol%, tar <3 vol%.

10. The application of purified syngas obtained by the gasification method according to any one of claims 6-8 in the fuel field or chemical synthesis field.

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