Low-calorific-value raw material gasification device and method

Abstract

The invention discloses a low-calorific-value raw material gasification device and a low-calorific-value raw material gasification method. The low-calorific-value raw material gasification device comprises a furnace body, a centrifugal separation assembly and a dust removal assembly, the furnace body comprises a combustion section and a gasification section, and the furnace body is provided with a first gas outlet and a first solid material circulation opening; fluid discharged from the first gas outlet is subjected to gas-solid two-phase separation after flowing into the centrifugal separation assembly, a gas-phase flow and a solid-phase flow are obtained, the solid-phase flow can be settled and accumulated in the centrifugal separation assembly and is constructed into a circulating solid material, and the first discharging opening is connected with the first solid material circulating opening of the furnace body; the synthesis gas after the gas phase flows through the dust removal assembly for dust removal is discharged from the third gas outlet, and the second feed opening is connected with the centrifugal separation assembly or the first solid material circulation opening of the furnace body. The gasification device for the low-calorific-value raw materials can perform gasification treatment on the low-calorific-value raw materials, is wide in application range, and meanwhile can reduce the carbon content of discharged bottom ash and discharged fly ash, improve the conversion rate in the gasification process and improve the energy utilization rate.

Description

Technical Field

[0001] This invention relates to the field of gasification equipment technology, and more specifically to a low-calorific-value feedstock gasification device and method. Background Technology

[0002] Gasification can transform solid feedstocks into gas molecules (such as hydrogen, carbon monoxide, methane, and carbon dioxide) under certain temperature and pressure conditions. However, all gasification methods in related technologies require high-calorific-value materials such as high-quality coal as feedstocks for gasification.

[0003] Low-calorific-value feedstocks are characterized by difficulty in ignition, unstable ignition, high ash content, low ash melting point, and difficulty in grinding biomass fibers into powder. Therefore, they are difficult to apply in fixed-bed and fluidized-bed gasifiers. Although fluidized-bed gasifiers can accept low-calorific-value feedstocks, the high carbon content in their bottom ash and fly ash results in low carbon conversion rate and low energy efficiency during the gasification process. Summary of the Invention

[0004] This invention is based on the inventor's discoveries and understanding of the following facts and problems: The inventors recognized that low-calorific-value raw materials can include biomass, municipal waste, and low-rank coals with high ash and moisture content, such as lignite. The low calorific-value characteristic of these raw materials is often accompanied by high levels of non-heat-generating impurities, such as high moisture, high ash, high oxygen content, or other impurities. Therefore, low-calorific-value raw materials are often associated with unstable strength.

[0005] The inventors also recognized that fixed-bed gasifiers require the use of high-quality lump coal (10~50mm) as raw material, and that fixed-bed gasifiers also have environmental problems such as large wastewater volume; fluidized bed gasifiers are high-efficiency gasifiers with large processing capacity and good environmental performance, but the gasification raw materials need to be ground into fine powder (such as less than 100um), and there are strict requirements for the quality of the raw materials, such as high calorific value, low ash content, and low ash fusion, otherwise the operating temperature of the gasifier is difficult to guarantee. Conventional fluidized bed gasifiers use crushed coal (0-10mm) as raw material, with slightly wider requirements than the two types of gasifiers mentioned above. Their operating temperature is moderate (900-1000°C). To achieve the desired gasification reaction, fluidized bed gasifiers need to maintain a certain carbon content (e.g., 10-25%) in the material within the gasifier. The ash discharged has a high carbon content (similar to the bed material). Fine coal has a short residence time in the gasifier, resulting in high carbon content in the fly ash. Therefore, fluidized bed gasifiers have always suffered from a "top-down" problem: the bottom ash has a high carbon content, and the fly ash has an even higher carbon content, leading to low carbon conversion rate and low energy efficiency during gasification. Furthermore, the processing capacity of such gasifiers is limited, making them unsuitable for large-scale chemical production. Therefore, fixed-bed gasifiers, entrained flow gasifiers, and fluidized bed gasifiers in related technologies are all difficult to use for gasifying low-calorific-value feedstocks.

[0006] The present invention aims to at least partially solve one of the technical problems in the related art.

[0007] Therefore, embodiments of the present invention propose a low-calorific-value raw material gasification device, which can perform gasification treatment of low-calorific-value raw materials, has a wide range of applications, and can reduce the carbon content of bottom ash and fly ash, improve the conversion rate of the gasification process, and improve energy utilization.

[0008] The embodiments of the present invention provide a method for gasifying low-calorific-value feedstocks.

[0009] The low-calorific-value feedstock gasification device of this invention includes: The furnace body includes a combustion section and a gasification section located above the combustion section. The upper part of the furnace body has a first gas outlet connected to the gasification section, and the lower part of the furnace body has a first solid material circulation port connected to the combustion section. A centrifugal separation component has a first feed inlet, a second air outlet, and a first discharge outlet. The first feed inlet is connected to the first air outlet. After the fluid discharged from the first air outlet flows into the centrifugal separation component, gas and solid phases separate to obtain a gas phase flow and a solid phase flow. The solid phase flow can settle and accumulate in the centrifugal separation component and form a circulating solid material. The first discharge outlet is connected to the first solid material circulation port of the furnace body. The dust removal component has a second feed inlet, a third air outlet, and a second discharge outlet. The second feed inlet of the dust removal component is connected to the second air outlet. The gas phase flow in the centrifugal separation component can enter the dust removal component through the second air outlet. The synthesis gas after dust removal by the dust removal component is discharged through the third air outlet. The second discharge outlet is connected to the first solid material circulation port of the centrifugal separation component or the furnace body, so that the powder separated in the dust removal component can be transported into the centrifugal separation component or the furnace body through the second discharge outlet.

[0010] The low-calorific-value raw material gasification device of this invention can gasify low-calorific-value raw materials such as low-quality coal and biomass. It has a wide range of raw material applications, strong processing capacity, and can realize large-scale industrial production applications. In this embodiment, the gas phase and solid phase of the fluid discharged from the gasification section are separated by a centrifugal separation component, and the syngas is further purified by a dust removal component, thereby reducing the fly ash content in the syngas. At the same time, the circulating solid and powder materials in the centrifugal separation component and the dust removal component can be recycled back into the furnace body to realize a large circulation of solid materials, thereby enabling the carbon substances to burn completely, reducing the carbon content of the bottom ash and fly ash, improving the conversion rate of the gasification process, and improving the energy utilization rate.

[0011] In some embodiments, the centrifugal separation assembly includes a centrifugal tube and a circulating feed leg. The centrifugal tube is arc-shaped, with a first end of the centrifugal tube configured as the first feed inlet, a second end of the centrifugal tube communicating with the upper part of the circulating feed leg, a second air outlet located at the upper part of the circulating feed leg, and the second air outlet and the second end of the centrifugal tube being spaced apart in the circumferential direction of the circulating feed leg. The first discharge port is located at the lower part of the circulating feed leg. The fluid discharged from the first outlet flows into the centrifuge tube and undergoes gas-solid two-phase separation to obtain a gas phase flow and a solid phase flow. The circulating material leg has a material cavity, and the upper part of the material cavity is constructed as an inertial separation section so that the solid phase flow can settle and accumulate in the material cavity and form the circulating solid material.

[0012] In some embodiments, the material chamber of the circulating material leg extends vertically, and the angle between the airflow direction at the second end of the centrifuge tube and the vertical direction is less than a first threshold.

[0013] In some embodiments, the second end of the centrifuge tube is disposed adjacent to the first side of the circulating feed leg, and the solid phase flow discharged from the second end of the centrifuge tube is closer to the inner wall surface of the first side of the circulating feed leg than the gas phase flow.

[0014] In some embodiments, the second air outlet and the second end of the centrifuge tube are respectively located on opposite sides of the circulating material leg in the circumferential direction; And / or, in the projection along the axial direction of the circulating material leg, the second air outlet and the centrifuge tube are misaligned; And / or, the centrifuge tube is an arc-shaped tube, and the central angle between the first end and the second end of the centrifuge tube is greater than or equal to 90 degrees and less than or equal to 180 degrees.

[0015] In some embodiments, the dust removal assembly is a cyclone separator, the cyclone separator includes a cylinder, a second feed inlet, a third air outlet and a second discharge outlet are provided on the cylinder, the second feed inlet on the cylinder and the second air outlet on the centrifugal separation assembly are connected by a guide pipe, the guide pipe is connected to the cylinder but not tangential; The cylinder is provided with an inner liner, and a guide block is provided at one end of the inner cavity of the guide tube adjacent to the cylinder. The guide block is used to guide the gas phase flow in the guide tube to enter the inner cavity of the inner liner along the tangential direction of the inner cavity of the inner liner.

[0016] In some embodiments, the inner liner is coaxially sleeved with the cylinder, or the inner liner is offset relative to the cylinder; And / or, in the projection of the cylinder along its axial direction, the axis of the guide tube intersects the axes of the cylinder and the inner liner, or the axis of the guide tube is offset relative to the axis of at least one of the cylinder and the inner liner.

[0017] In some embodiments, the system further includes a first circulation pipe and a second circulation pipe. The first circulation pipe is disposed between the first feed inlet of the centrifugal separation component and the first solid material circulation inlet of the furnace body. The centrifugal separation component has a second solid material circulation inlet, and the second circulation pipe is disposed between the second feed inlet of the dust removal component and the second solid material circulation inlet of the centrifugal separation component. The first discharge port is higher in the vertical direction than the first solid material circulation port, the second discharge port is higher in the vertical direction than the second solid material circulation port, the angle between the axis of the first circulation pipe and the horizontal plane is greater than or equal to 45 degrees, and the angle between the axis of the second circulation pipe and the horizontal plane is greater than or equal to 45 degrees.

[0018] In some embodiments, the first discharge port and the second solid material circulation port are both located below the material surface of the circulating solid material in the centrifugal separation component in the vertical direction, and the height of the second solid material circulation port in the vertical direction is higher than the height of the first discharge port. And / or, the angle between the axis of the first circulation tube and the horizontal plane is greater than or equal to 50 degrees and less than or equal to 60 degrees, and the angle between the axis of the second circulation tube and the horizontal plane is greater than or equal to 50 degrees and less than or equal to 60 degrees.

[0019] In some embodiments, the furnace body includes a plurality of feeding ports, which are connected to the gasification section, and a portion of the plurality of feeding ports is higher in the vertical direction than another portion of the plurality of feeding ports.

[0020] In some embodiments, the furnace body includes a plurality of gasifying agent inlets, all of which are connected to the combustion section. The plurality of gasifying agent inlets are divided into multiple gasifying agent inlet groups, each gasifying agent inlet group including at least one gasifying agent inlet. The multiple gasifying agent inlet groups are arranged at intervals along the axial direction of the combustion section. When a gasifying agent inlet group includes multiple gasifying agent inlets, the multiple gasifying agent inlets located in the same gasifying agent inlet group are arranged at intervals along the circumferential direction of the combustion section. At least part of the gasifying agent inlet is located below the first solid material circulation port, and the gas flow direction of the gasifying agent inlet is inclined upward.

[0021] In some embodiments, the furnace body includes a first ash discharge port and a second ash discharge port, the first ash discharge port being located at one end of the combustion section adjacent to the gasification section, and the second ash discharge port being located at the bottom of the furnace body.

[0022] In some embodiments, the furnace body includes a fly ash circulation port, a fly ash circulator is provided at the fly ash circulation port, the fly ash circulation port is connected to the combustion section and located above the first solid material circulation port, the synthesis gas discharged from the third gas outlet of the dust removal assembly is washed to obtain fly ash slurry, and the fly ash circulator is used to burn and gasify the fly ash slurry and then transport it into the combustion section.

[0023] In some embodiments, the raw materials used in the low-calorific-value feedstock gasification device include at least one of coal and biomass. The coal has a particle size of less than 2 mm and a moisture content of less than or equal to 30%. The biomass is formed by compression granulation, and the particle size of the biomass is 5 mm to 20 mm, with a moisture content of less than or equal to 35%. When using biomass, the temperature inside the furnace body is 650 degrees Celsius to 950 degrees Celsius. When using coal, the temperature inside the furnace body is 850 degrees Celsius to 1200 degrees Celsius. And / or, the particle size of the recycled solids is from 45 micrometers to 1000 micrometers; And / or, the apparent velocity of the fluid in the combustion section is 3 m / s to 8 m / s, and the apparent velocity of the fluid in the gasification section is 5 m / s to 10 m / s; And / or, the pressure of the furnace body is 1 MPa to 6 MPa; And / or, the ratio of the flow rate of the circulating solid material delivered into the furnace body from the first solid material circulation port to the flow rate of the raw material newly added into the furnace body is 50 to 100.

[0024] This invention provides a method for gasifying low-calorific-value raw materials, which utilizes the low-calorific-value raw material gasification device described in any of the above embodiments to perform the gasification operation of the raw materials.

[0025] In some embodiments, during the initial operation of the low-calorific-value raw material gasification device, granular material is added to the centrifugal separation component as circulating solid material. And / or, when the feedstock fed into the low-calorific-value feedstock gasification device is biomass feedstock, aluminum-containing inorganic additives are added to the furnace body. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of a low-calorific-value feedstock gasification device according to an embodiment of the present invention.

[0027] Figure 2 This is a schematic diagram of the centrifugal separation component in an embodiment of the present invention.

[0028] Figure 3 This is a schematic diagram showing the positions of the centrifuge tube and the second air outlet in an embodiment of the present invention.

[0029] Figure 4 This is a schematic diagram showing the positions of the centrifuge tube and the second air outlet in another embodiment of the present invention.

[0030] Figure 5 This is a schematic diagram showing the connection between the cyclone separator and the circulating material leg in an embodiment of the present invention.

[0031] Figure 6 This is a schematic diagram showing the connection between the guide pipe and the cylinder of the cyclone separator in an embodiment of the present invention.

[0032] Figure 7 This is a schematic diagram showing the connection between the guide pipe and the cylinder of the cyclone separator in another embodiment of the present invention.

[0033] Figure 8 This is a schematic diagram of the connection of the first circulation tube in an embodiment of the present invention.

[0034] Figure 9 This is a schematic diagram of the furnace body in an embodiment of the present invention.

[0035] Figure label: 100. Low-calorific-value feedstock gasification unit; 1. Furnace body; 11. Combustion section; 12. Gasification section; 13. First gas outlet; 14. First ash discharge port; 15. Second ash discharge port; 16. Feed port; 17. Gasifying agent inlet; 18. First solid material circulation port; 19. Fly ash circulation port; 191. Fly ash circulator; 2. Centrifugal separation assembly; 21. Separation pipe; 22. Circulating material leg; 221. Inertial separation section; 23. First feed inlet; 24. Second air outlet; 25. First discharge port; 26. Second solid material circulation port; 27. Circulating solid material; 28. Solid phase flow; 29. ​​Gas phase flow; 3. Dust removal assembly; 31. Second feed inlet; 32. Third air outlet; 34. Second discharge outlet; 35. Cylinder body; 36. Inner liner; 41. First circulation pipe; 42. Second circulation pipe; 5. Flow guide pipe; 51. Flow guide block. Detailed Implementation

[0036] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0037] The inventors recognized that under rapid heating conditions, the solid fine particles of the gasification feedstock rapidly heat up, dehydrate and dry, and then undergo pyrolysis. The intermediate products generated by rapid pyrolysis immediately react with the surrounding gasifying agent molecules (water vapor, carbon dioxide, and hydrogen, etc.), reducing or avoiding the repolymerization of pyrolysis free radicals. These reactions result in smaller pyrolysis product semi-tar molecules, which have higher reactivity in subsequent gasification reactions. At the same time, the medium-sized tar molecules that may be generated by pyrolysis are quickly further reacted into smaller molecules. Therefore, under rapid pyrolysis conditions, almost no tar is produced during gasification, or the amount of tar is very small. Even if some intermediate tar is still produced, it will be converted into small molecules after reacting with the gasifying agent. The final gasification products do not contain large tar molecules.

[0038] The inventors also recognized that biomass generally has a high volatile content, and among the volatiles, methane content is high, especially under rapid heating conditions, the content of small molecules such as methane is higher than that obtained from general low-speed pyrolysis processes. Methane itself is one of the cleanest fuels and a basic chemical raw material; how to directly utilize this portion of methane is an important consideration in the organization of the gasification process.

[0039] The inventors also recognized that in the separation equipment of gasification devices in related technologies, solid particles are basically uniformly dispersed in the gas flow, and are generally uniformly distributed in a dilute phase. When gas and solid particles enter the top of the separation cylinder, the gas begins to diffuse, and some solid particles are also diffused with the gas, causing the fluid to flow downwards in a funnel shape. Most solid particles have greater inertia than gas, and the solid particles tend to continue flowing downwards, while the gas, having no passageway within the separation cylinder, must turn upwards until it leaves the outlet. During the process of the gas turning upwards and converging towards the gas outlet, due to the high gas velocity, it will carry solid particles along with it until it exits the separation cylinder. Therefore, the separation efficiency of the separation equipment in related technologies is low, only between 60% and 80%. This results in a still high solid load entering the secondary separator, ultimately affecting the overall separation efficiency. A large amount of solid is carried out of the gasification system, leading to a decreasing amount of solid in the main circulation of the gasification equipment, making it impossible to maintain a stable system cycle.

[0040] The inventors also recognized that in high-speed circulating systems, when a cyclone separator is used for the primary separation stage of gas-solid separation, the inlet velocity of the cyclone separator needs to be set relatively low due to the high concentration of entrained solids in the gas during the large circulation process. Otherwise, not only will the pressure loss be significant, but the wear on the equipment will also be substantial. Therefore, a relatively low inlet velocity (such as below 10 m / s) is generally chosen. However, the low inlet velocity results in a large cyclone dust collector, making manufacturing difficult, installation costs high, and the support structure complex. Even so, the separation efficiency of the cyclone separator as the primary stage is still insufficient, and further improvement in the primary gas-solid separation efficiency is still needed.

[0041] Therefore, this invention provides a low-calorific-value raw material gasification device 100, which can be used for low-rank coals with high ash and moisture content, such as lignite, and can also be applied to biomass raw materials such as municipal waste, animal excrement, and plant waste.

[0042] See Figures 1 to 9 The low-calorific-value raw material gasification device 100 of this invention includes a furnace body 1, a centrifugal separation component 2, and a dust removal component 3.

[0043] The furnace body 1 includes a combustion section 11 and a gasification section 12 located above the combustion section 11. The upper part of the furnace body 1 has a first gas outlet 13 connected to the gasification section 12. The syngas generated by the gasification section 12 carries solid particles and is discharged from the furnace body 1 through the first gas outlet 13. The lower part of the furnace body 1 has a first solid material circulation port 18 connected to the combustion section 11. The first solid material circulation port 18 is used to circulate the solid materials separated by the centrifugal separation component 2 and the dust removal component 3 back into the furnace body 1 for complete combustion, thereby improving energy utilization and reducing the carbon content in emissions.

[0044] The centrifugal separation component 2 has a first feed inlet 23, a second air outlet 24, and a first discharge outlet 25. The first feed inlet 23 is connected to the first air outlet 13. The fluid discharged from the first air outlet 13 undergoes gas-solid two-phase separation after flowing into the centrifugal separation component 2, resulting in a gas phase flow and a solid phase flow. The solid phase flow can settle and accumulate within the centrifugal separation component 2, forming a circulating solid material 27. The first discharge outlet 25 is connected to the first solid material circulation port 18 of the furnace body 1. This embodiment utilizes the centrifugal principle to separate the gas and solid phases, thereby enabling more targeted solid phase sedimentation, directing the gas phase flow towards the dust removal component 3, and reducing the amount of solid particles carried by the gas phase when flowing into the dust removal component 3. This achieves effective separation of solid particles, with a separation efficiency of 90% or even over 95%, significantly reducing the load on the subsequent dust removal component 3 and making the entire system more stable.

[0045] The dust removal component 3 has a second feed inlet 31, a third air outlet 32, and a second discharge port 34. The second feed inlet 31 of the dust removal component 3 is connected to the second air outlet 24. The gas phase flow in the centrifugal separation component 2 can enter the dust removal component 3 through the second air outlet 24. The syngas after dust removal by the dust removal component 3 is discharged through the third air outlet 32. The second discharge port 34 is connected to the first solid material circulation port 18 of the centrifugal separation component 2 or the furnace body 1, so that the powder separated in the dust removal component 3 can be transported into the centrifugal separation component 2 or the furnace body 1 through the second discharge port 34. Since the operating load of the dust removal component 3 is low, the operating parameters of the dust removal component 3 can be optimized to improve the dust removal effect of the dust removal component 3 and reduce the fly ash content in the syngas discharged from the third air outlet 32. This ensures that the amount of solid material collected by the centrifugal separation component 2 and the dust removal component 3 meets the large circulation requirements of the gasification device, thereby maintaining the stable and continuous circulation operation of the system.

[0046] The low-calorific-value raw material gasification device 100 of this invention can gasify low-quality coal raw materials and low-calorific-value biomass raw materials. It has a wide range of raw material applications, strong processing capacity, and can realize large-scale industrial production applications. In this embodiment, the gas phase and solid phase of the fluid discharged from the gasification section 12 are separated by the centrifugal separation component 2, and the syngas is further purified by the dust removal component 3. This can reduce the fly ash content in the syngas. At the same time, the circulating solid material 27 and powder in the centrifugal separation component 2 and the dust removal component 3 can be recycled back to the furnace body 1 to realize a large circulation of solid materials. This allows carbon substances to be fully combusted, reduces the carbon content of the bottom ash and fly ash, improves the conversion rate of the gasification process, and improves the energy utilization rate.

[0047] See Figure 2 In some embodiments, the centrifugal separation assembly 2 includes a centrifugal tube 21 and a circulating material leg 22. The centrifugal tube 21 is arc-shaped. The first end of the centrifugal tube 21 is configured as a first feed inlet 23. The second end of the centrifugal tube 21 is connected to the upper part of the circulating material leg 22. The second air outlet 24 is located at the upper part of the circulating material leg 22, and the second air outlet 24 and the second end of the centrifugal tube 21 are spaced apart in the circumferential direction of the circulating material leg 22. The first discharge port 25 is located at the lower part of the circulating material leg 22.

[0048] The fluid discharged from the first outlet 13 flows into the centrifuge tube 21 and undergoes gas-solid two-phase separation to obtain gas flow and solid flow. The circulating material leg 22 has a material chamber, and the upper part of the material chamber is constructed as an inertial separation section 221 so that the solid flow can settle and accumulate in the material chamber and be constructed as circulating solid material 27.

[0049] Gas-solid separation is the core of ensuring the large-scale solid circulation in this embodiment. The gas-solid separation in this embodiment is completed in three stages. The first stage is to use an arc-shaped centrifuge tube 21 to complete the gas-solid two-phase separation under the action of centrifugal force, thereby obtaining an aggregated solid particle flow (i.e., solid phase flow) and a gas flow containing very few solid particles (i.e., gas phase flow). The second stage involves inertial separation using the circulating feed leg 22. The two fluids separated from the centrifuge tube 21 enter the top of the circulating feed leg 22. The feed chamber of the circulating feed leg 22 extends in a generally vertical direction (i.e., the up-down direction shown in the figure). The angle between the airflow direction at the second end of the centrifuge tube 21 and the vertical direction is less than a first threshold. The first threshold can be 3 degrees, 5 degrees, 10 degrees, 15 degrees, 16 degrees, etc. It can be understood that the solid phase flow and gas phase flow flowing into the inner cavity of the circulating feed leg 22 from the second end of the centrifuge tube 21 both flow into the circulating feed leg 22 in a generally vertical direction. Of course, they can also be slightly inclined relative to the vertical direction. This embodiment takes the example of the solid phase flow and gas phase flow flowing into the circulating feed leg 22 in a generally vertical direction for explanation.

[0050] The upper part of the material cavity in the circulating material leg 22 is the inertial separation section 221, and the lower part of the material cavity in the circulating material leg 22 is the circulating solid material section 27. After the solid phase flow and the gas phase flow enter the circulating material leg 22 in the vertical direction, the two fluids flow downward in their respective areas with their own inertial velocities. Due to the difference in fluid density, the fluid kinetic energy is different. The downward inertia of the aggregated solid particle flow (i.e., solid phase flow) is greater than that of the gas flow (i.e., gas phase flow). The solid particle flow continues to move downward until it reaches the solid surface in the circulating material leg 22 (i.e., the surface of the circulating solid material 27) and stops.

[0051] After the gas flow enters the inertial separation section 221 of the circulating material leg 22, since the area below the inertial separation section 221 is a non-flowing zone with no outlet, part of the kinetic energy of the rapidly flowing gas is converted into higher static pressure potential energy during the downward process. The high static pressure forces the gas to turn and move towards the low-pressure area, and the gas flow is deflected upward until it flows out from the second gas outlet 24 at the top of the inertial separation section 221.

[0052] Throughout the process, the outflow trajectory of the gas phase flow is almost completely separated from the flow of aggregated solid particles. When the gas exits from the inertial separation section 221, it carries almost no large-diameter solid particles. Only finer dust-like solids (such as <45µm) may leave the inertial separation section 221 with the gas. Thus, the combined action of the arc-shaped centrifuge tube 21 and the inertial separation section 221 of the circulating material leg 22 achieves efficient separation of the main solid particles from the gas. In the actual working system, the circulating solid material 27 is composed of solid particles of different diameters. Most of the larger diameter particles can be separated from the gas in the inertial separation section 221 of the centrifuge tube 21 and the circulating material leg 22. However, smaller particles, such as those less than 45µm, may not be separated from the gas at this stage and are instead carried along with the gas from the inertial separation section 221.

[0053] The third stage of gas-solid separation involves using dust removal component 3 to further separate residual small particles.

[0054] In some embodiments, such as Figure 2 As shown, the second end of the centrifuge tube 21 is positioned adjacent to the first side of the circulating feed leg 22. Figure 2 The right side of the circulating material leg 22 can be the first side, and the solid phase flow discharged from the second end of the centrifuge tube 21 is closer to the inner wall of the first side of the circulating material leg 22 than the gas phase flow. This allows the solid phase flow to be closer to the side wall of the first side of the inertial separation section 221 of the circulating material leg 22, reserving more space for the gas phase flow. This prevents interference and convection between the gas phase flow and the solid phase flow when the gas phase flow turns within the inertial separation section 221, reducing the amount of solid particles carried by the gas phase flow when it flows out of the second outlet 24.

[0055] Figure 1 The diagram shows that the second end of the centrifuge tube 21 is connected to the top left side of the circulating feed leg 22. At this time, the gas phase flow discharged from the second end of the centrifuge tube 21 is closer to the inner wall surface of the left side of the circulating feed leg 22 than the solid phase flow. Figure 1 The diagram shown is merely illustrative and represents one embodiment of this application. To ensure that the solid phase flow discharged from the second end of the centrifuge tube 21 is closer to the right inner wall of the circulating feed leg 22 than the gas phase flow, the second end of the centrifuge tube 21 needs to be connected to... Figure 1 The second air outlet 24 is located on the top right side of the circulating feed leg 22 shown in the diagram. To avoid the second air outlet 24 being located near the second end of the centrifuge tube 21, the second air outlet 24 can be positioned adjacent to... Figure 1 The upper left side of the circulating material leg 22 shown in the diagram allows for the implementation of the structure of this embodiment, as follows: Figure 2 As shown.

[0056] See Figure 3Furthermore, the second air outlet 24 and the second end of the centrifuge tube 21 are respectively located on opposite sides of the circulating material leg 22 in the circumferential direction. This allows for the optimal solid separation effect to be achieved by utilizing the relative positional relationship between the second end of the centrifuge tube 21 and the second air outlet 24.

[0057] Specifically, the solid particle flow (i.e., solid phase flow) is furthest from the second outlet 24. The centrifuge tube 21 is connected to the top of the inertial separation section 221, ensuring that both fluid streams from the centrifuge tube 21 flow vertically downwards. The exit point of the solid particle flow is positioned close to the inner wall of the first side of the inertial separation section 221. The second outlet 24 is located at the top of the inertial separation section 221, and its position is opposite to the exit point of the solid particle flow, ensuring that the second outlet 24 is furthest from the solid particle flow. This minimizes the impact of the complex flow trajectory of the gas flow within the inertial separation section 221 on the solid particle flow, achieving the highest gas-solid separation efficiency. Simultaneously, spatially, the centrifuge tube 21 is above, and the second outlet 24 is directly below. In other words, in the projection along the axis of the circulating material leg 22, the projections of the centrifuge tube 21 and the second outlet 24 overlap.

[0058] In some embodiments, see Figure 4 In the projection along the axial direction of the circulating material leg 22, the second air outlet 24 and the centrifuge tube 21 are misaligned.

[0059] In practical implementation, the space required for the arrangement of the equipment connected to the second outlet 24 needs to be considered. If the space below the centrifuge tube 21 is limited, the aforementioned scheme of overlapping the projections of the centrifuge tube 21 and the second outlet 24 cannot be adopted. Therefore, the second outlet 24 needs to be offset from the centrifuge tube 21 by a certain angle. This facilitates the arrangement of pipes and equipment connected to the second outlet 24 and also ensures that the gas outlet is as far away as possible from the falling area of ​​the aggregated solid particles. In other words, in the projection along the axial direction of the circulating material leg 22, the second outlet 24 and the centrifuge tube 21 are staggered. This ensures that the circumferential distance between the second outlet 24 and the second end of the centrifuge tube 21 on the circulating material leg 22 is sufficiently large, thus preventing the pipes and equipment connected to the second outlet 24 from being affected by the space below the centrifuge tube 21, resulting in better practicality.

[0060] Furthermore, in this embodiment, the centrifuge tube 21 is an arc-shaped tube, and the central angle between the first end and the second end of the centrifuge tube 21 is greater than or equal to 90 degrees and less than or equal to 180 degrees. The central angle between the first end and the second end of the centrifuge tube 21 can be 90 degrees, 100 degrees, 120 degrees, 145 degrees, 160 degrees, or 180 degrees. The size of the central angle of the centrifuge tube 21 can be determined according to the relative position and relative height of the furnace body 1 and the circulating material leg 22, the airflow direction of the first gas outlet 13, etc. At the same time, the size of the central angle can also be determined according to the aggregation effect of solid particles during centrifugation, thereby ensuring the separation effect of gas and solid phases.

[0061] In related technologies, the cyclone dust collector structure uses a tangential inlet, which is not problematic in principle or in practice. However, with the increasing scale and size of industrial production facilities, modern coal chemical gasification equipment requires high pressure (generally 4.0 MPa or higher). Large-size, high-pressure equipment is the development trend. Cyclone separators in related technologies face unique challenges in large-circulation high-pressure applications. Specifically, the connection between the gas inlet pipe (guide pipe 5 in this embodiment) and the cylinder 35 tangentially requires a large irregular opening on the cylinder 35. This irregular structure, combined with the tangential connection, necessitates a thicker wall for the cyclone dust collector cylinder 35. For example, when the cylinder 35 diameter is 2000 mm and the operating pressure reaches 4.0 MPa, the thickness of the outer metal shell of the cylinder 35 needs to be over 200 mm. This thickness is significantly higher than the required wall thickness of the cylinder 35 under the same conditions (e.g., 40 mm), thus significantly increasing manufacturing difficulty and equipment cost. The increased weight of the equipment also places stricter requirements on installation and support.

[0062] Therefore, such as Figures 5 to 7 As shown, in some embodiments of the present invention, the dust removal component 3 is a cyclone separator. The cyclone separator includes a cylinder 35, a second feed inlet 31, a third air outlet 32, and a second discharge outlet 34 disposed on the cylinder 35. The second feed inlet 31 on the cylinder 35 is connected to the second air outlet 24 on the centrifugal separation component 2 via a guide pipe 5. The guide pipe 5 is connected to the cylinder 35 but not tangential to it. An inner liner 36 is provided inside the cylinder 35. A guide block 51 is provided at one end of the inner cavity of the guide pipe 5 adjacent to the cylinder 35. The guide block 51 is used to guide the gas phase flow in the guide pipe 5 into the inner cavity of the inner liner 36 along the tangential direction of the inner cavity of the inner liner 36.

[0063] This embodiment employs a metal outer shell tee structure to connect the guide pipe 5 and the cylinder 35. This makes it easier to meet the requirement that the wall thickness of the cylinder 35 be increased due to the opening, thus significantly reducing the wall thickness requirement. Under the condition that the metal outer shells of the cylinder 35 and the guide pipe 5 are conventionally configured, it is necessary to maintain the structural requirement of tangential airflow entry into the cyclone separator. This can be achieved through the structural configuration of refractory materials (i.e., the inner liner 36 and the guide block 51 in this embodiment). The guide pipe 5 in this embodiment can also be fitted with a refractory liner.

[0064] Optionally, such as Figure 6 As shown, the inner liner 36 is coaxially sleeved with the cylinder 35. At this time, the inner liner 36, made of refractory material, is concentric with the cylinder 35. The tangential flow pattern of the fluid is mainly formed by the guiding effect of the guide block 51 made of refractory material inside the guide pipe 5. In the projection along the axial direction of the cylinder 35, the axis of the guide pipe 5 can intersect with the axes of the cylinder 35 and the inner liner 36.

[0065] Optionally, such as Figure 7 As shown, the inner liner 36 is offset relative to the cylinder 35, making the flow direction of the fluid in the guide block 51 inside the guide pipe 5 closer to the tangential direction of the inner wall of the inner liner 36 inside the cylinder 35. Combined with the guidance of the guide block 51 inside the inlet pipe, the gas-solid separation effect is improved. In the projection along the axial direction of the cylinder 35, the axis of the guide pipe 5 is offset relative to at least one of the axes of the cylinder 35 and the inner liner 36. For example, the projection of the axis of the guide pipe 5 does not intersect with the projections of the axes of the cylinder 35 and the inner liner 36. In this case, the wall thickness of different circumferential regions of the cylinder 35 can also be optimized.

[0066] In gasifiers with solid circulation, a material sealing structure for the feed legs is typically designed to prevent gas backflow between the two fluids, which would affect the solid flow. Otherwise, the solid flow would be unstable, and the circulation temperature would be unreliable. The material sealing structure uses multiple sections of bent pipes connected together to prevent gas from returning from the solid outlet to the solid particle inlet. Furthermore, in some sections of the pipe, the solid material flows upwards. This is because if gas backflow were to occur, the solid material in those sections would suddenly stop flowing and accumulate. The gas would then have difficulty overcoming the resistance of this accumulation, thus effectively preventing gas backflow. However, the flow characteristics of solid particles are such that downward flow is driven by gravity, while in the upward flow section of the structure, solids tend to settle and require the external force of fluidizing gas to propel them upwards. The horizontal movement of solid particles also requires the assistance of fluidizing gas. In industrial plants, especially high-pressure circulating systems, the large amount of fluidizing gas required is generally supplied by inert gases such as nitrogen. However, for coal gasification to produce syngas, nitrogen is an ineffective gas; its addition dilutes the gas generated in the gasifier and reduces its calorific value. To avoid the adverse effects of nitrogen, the industrial implementation employs a method of syngas recirculation at the gasifier outlet. This involves cooling, washing, and dust removal of the outlet syngas before it is pressurized by a compressor and fed into the feed sealing structure as fluidizing gas. The required amount of fluidizing gas is substantial, typically around 10% of the gas volume at the gasifier outlet. The higher the gasifier pressure, the greater the amount of fluidizing gas needed to maintain the same gas flow rate. This increases the complexity of the process and raises production and operating costs.

[0067] Therefore, in some embodiments of the present invention, a first circulation pipe 41 and a second circulation pipe 42 are provided. The first circulation pipe 41 is located between the first discharge port 25 of the centrifugal separation component 2 and the first solid material circulation port 18 of the furnace body 1. The centrifugal separation component 2 has a second solid material circulation port 26, which is located on the circulating material leg 22. The second circulation pipe 42 is located between the second discharge port 34 of the dust removal component 3 and the second solid material circulation port 26 of the centrifugal separation component 2.

[0068] The first discharge port 25 is higher in the vertical direction than the first solid material circulation port 18, and the second discharge port 34 is higher in the vertical direction than the second solid material circulation port 26. The angle between the axis of the first circulation pipe 41 and the horizontal plane is greater than or equal to 45 degrees, and the angle between the axis of the second circulation pipe 42 and the horizontal plane is greater than or equal to 45 degrees. In this way, the solid particles can flow downward naturally by gravity. For example, the angle between the axis of the first circulation pipe 41 and the horizontal plane is greater than or equal to 50 degrees and less than or equal to 60 degrees, and the angle between the axis of the second circulation pipe 42 and the horizontal plane is greater than or equal to 50 degrees and less than or equal to 60 degrees.

[0069] Furthermore, the first discharge port 25 and the second solid material circulation port 26 are both located below the material surface of the circulating solid material 27 in the centrifugal separation component 2 in the vertical direction, and the height of the second solid material circulation port 26 in the vertical direction is higher than the height of the first discharge port 25.

[0070] In this embodiment, solid particles from the inertial separation section 221 of the upper part of the circulating material leg 22 continue to flow downward along the circulating material leg 22 in the vertical direction. The solid particles separated by the cyclone separator flow into the circulating material leg 22 through the second circulation pipe 42, and the two solid material streams flow together in the circulating material leg 22. The solid particles separated by the cyclone separator have a smaller particle size.

[0071] During the gasifier's circulating operation, the solid content in the circulating material leg 22 is controlled so that the material level in the circulating material leg 22 is higher than the second solid material circulation port 26 of the circulating material leg 22. This material level, higher than the second solid material circulation port 26, acts as a material seal, preventing the gas in the circulating material leg 22 from short-circuiting into the second circulation pipe 42 and the cyclone separator, thus avoiding affecting the separation efficiency of the cyclone separator.

[0072] Two solid streams from the inertial separation section 221 and the second circulation pipe 42 flow downwards according to gravity. After the two streams merge, a certain solid level is formed in each of the circulating material leg 22 and the second circulation pipe 42 to maintain flow balance. In actual operation, the solid level in the second circulation pipe 42 is higher than the material level in the circulating material leg 22. This height difference compensates for the pressure drop of the cyclone separator.

[0073] The above solid flow mixing method avoids the material sealing structure set up in related technologies and does not require the use of fluidizing gas, which simplifies the process, reduces production costs, and improves operational reliability in actual production.

[0074] In some embodiments, the furnace body 1 includes a plurality of feeding ports 16, which are correspondingly connected to the gasification section 12, and a portion of the plurality of feeding ports 16 is higher in the vertical direction than another portion of the plurality of feeding ports 16.

[0075] In the vertical direction, the feed port 16, located at a high position, is suitable for herbaceous plants, which have a high cellulose content, can be operated at a lower temperature, and have high gasification reactivity.

[0076] In the vertical direction, the lower-positioned feed port 16 is more suitable for woody plants, which have a higher lignin content and require a higher temperature for gasification. Furthermore, the gasification reaction takes a longer time, therefore the gasification section 12 needs to be longer. Low-rank coal also uses a lower-position feed port for its reaction.

[0077] The feeding port 16 in this embodiment can be designed in terms of height and number according to the different raw materials used. Therefore, the corresponding feeding port 16 can be selected for feeding according to the raw materials being added, which improves practicality.

[0078] See Figure 8 and Figure 9 In some embodiments, the furnace body 1 includes a plurality of gasifying agent inlets 17, all of which are connected to the combustion section 11. The plurality of gasifying agent inlets 17 are divided into a plurality of gasifying agent inlet groups 17, each gasifying agent inlet group 17 including at least one gasifying agent inlet 17. The plurality of gasifying agent inlet groups 17 are arranged at intervals along the axial direction of the combustion section 11. When a gasifying agent inlet group 17 includes a plurality of gasifying agent inlets 17, the plurality of gasifying agent inlets 17 located in the same gasifying agent inlet group 17 are arranged at intervals along the circumferential direction of the combustion section 11. At least some of the gasifying agent inlets 17 are located below the first solid material circulation port 18, and the airflow direction of the gasifying agent inlets 17 is inclined upward.

[0079] A gasifying agent, such as oxygen, water vapor, carbon dioxide, or air, is introduced into combustion section 11. Combustion section 11 also receives high-temperature circulating solid particles (i.e., circulating solid material 27) from the first circulation pipe 41. The gasifying agent flows upwards from the bottom of combustion section 11 at a high speed (5-10 m / s). The high-speed flowing gas entrains the circulating solid particles and flows upwards rapidly. During this flow, the hot circulating solid particles contain residual carbon that was not completely converted in the previous gasification reaction. This residual carbon immediately begins to burn upon encountering oxygen in the gasifying agent, releasing heat and raising the temperature of the gas and all solids. Because the circulating solid flow rate is much higher than the added raw material solids (circulation ratio between 50 and 100), the temperature rise is relatively low, generally between 50 and 100°C due to the large mass flow rate. The combustion reaction in combustion section 11 completely consumes the residual carbon. The carbon dioxide and water vapor generated by combustion enter the upper gasification section 12 as the gas for the next gasification reaction.

[0080] In the combustion section 11, oxygen and water vapor enter the furnace body 1 from bottom to top, allowing the gas to smoothly adjust its direction and flow upwards along the combustion section 11. At the bottom of the combustion section 11, the gasifying agent inlets 17 can be arranged in two or more layers, with three or more gasifying agent inlets 17 arranged circumferentially in each layer. The gasifying agent can enter the furnace body 1 in layers or simultaneously as needed for operation. Gasifying agent inlets 17 are also arranged below the junction of the combustion section 11 and the first circulation pipe 41. Water vapor or carbon dioxide is used to assist the flow of solid particles from the first circulation pipe 41. The gas itself is also a gasification reaction gas, therefore no additional fluidizing gas is required.

[0081] This embodiment includes a gasification section 12. In the gasification section 12, solid gasification feedstock (granular) is introduced through a feed port 16. After entering, the granular feedstock rapidly mixes with the large-circulation hot solid particles from the combustion section 11. Each particle is surrounded by 50 times or more hot solid particles, thus rapidly heating each individual particle. As the particles heat up, the moisture in the solid feedstock particles evaporates rapidly, followed by a pyrolysis reaction. Volatile components in the feedstock are rapidly released upon heating. Rapid pyrolysis differs from conventional slow-heating pyrolysis; it produces more small and medium-sized molecules as intermediates. Especially in an atmosphere containing active gases such as water vapor and carbon dioxide, intermediate free radicals no longer polymerize to form larger molecules. Therefore, the degree of polymerization of the residual semi-coke is low, which is beneficial to the subsequent gasification reaction rate of the semi-coke. The small-molecule gases obtained from pyrolysis, such as CH4 and H2, also yield medium-sized molecules, equivalent to coal tar-like intermediates. Under the operating temperature conditions, coal tar still appears in gaseous form. Another product of pyrolysis is solid semi-coke particle intermediates. During the continuous ascent in gasification section 12, small molecule intermediates of tar quickly undergo secondary gasification reactions with the gasifying agent (water vapor and carbon dioxide) to produce even smaller molecules (such as H2, CH4, and CO); while solid semi-coke particles also continue to undergo gasification reactions with the gasifying agent to generate CO and H2.

[0082] The syngas obtained from the above drying, pyrolysis, and gasification reactions, along with the circulating solids and a small amount of residual carbon that is not easily completely reacted, reach the top of gasification section 12. There, through efficient gas-solid separation, all larger solid particles are separated and continue to circulate as circulating solids. Only fine dust particles (e.g., less than 45 μm) leave the circulation loop with the gas.

[0083] The inorganic components in the gasification feedstock do not participate in the gasification reaction but instead form ash particles. Larger ash particles are separated by a high-efficiency gas-solid separator and remain in the circulation loop, participating in solid recycling. As a result, solid particles accumulate in the circulation loop, gradually increasing the material level in the circulation leg 22. During actual operation, the material level in the circulation leg 22 can be monitored using online instruments. When the level exceeds a set value, ash is discharged to remove a portion of the circulating solids, maintaining a stable solid material level in the circulation leg 22. This ensures the continuous and stable large-scale solid recycling process.

[0084] See Figure 9 Therefore, in this embodiment of the invention, a first ash outlet 14 and a second ash outlet 15 are provided. The first ash outlet 14 is located at one end of the combustion section 11 adjacent to the gasification section 12, and the second ash outlet 15 is located at the bottom of the furnace body 1.

[0085] The first ash discharge port 14 serves as the main ash discharge point. Located at the end of the combustion section 11, this port minimizes the carbon content in the circulating solids and reduces the amount of carbon carried away by the discharged ash, thus facilitating a higher carbon conversion rate. An ash discharge controller is installed at the first ash discharge port 14 to discharge high-temperature, high-pressure coarse ash from the gasifier's circulating loop.

[0086] The second ash discharge port 15 serves as an auxiliary ash discharge point. It is located at the bottom of the furnace body 1 and primarily discharges larger particles from the furnace, while also acting as a backup for the main ash discharge. An ash discharge controller is installed at the second ash discharge port 15 to discharge high-temperature, high-pressure coarse ash from the gasifier's circulation loop.

[0087] The inventors recognized that, due to the low carbon content in the recycled solid feed, the carbon content in the discharged ash solids is generally less than 1%, and in practice, it can be less than 0.1%. On the other hand, the raw material particles can reside in the gasifier for a long time, such as 5 seconds or longer, allowing sufficient reaction time in the gasifier reactor to improve the degree of reaction and carbon conversion rate. Therefore, the carbon conversion rate of the gasification process in this invention is significantly higher than that of conventional fluidized bed gasifiers in terms of both carbon conversion rate and energy utilization. Thus, the overall carbon conversion rate of the gasification process is high (e.g., above 98%), and the energy conversion efficiency is high. The carbon conversion rate of the gasification process in this invention is much higher than that of conventional fluidized bed gasifiers (generally 85%~93%), thereby solving the problem of "spitting out and draining" in conventional fluidized bed gasifiers.

[0088] Although, as mentioned above, the large-scale circulation of the gasification unit can significantly improve the carbon conversion rate, some extremely fine fly ash still leaves the gasifier. This fly ash contains a certain amount of carbon, and this carried-over carbon is the main reason why the carbon conversion rate does not reach 100%. In this embodiment, the furnace body 1 is provided with a fly ash circulation port 19, and a fly ash circulator 191 is provided at the fly ash circulation port 19. The fly ash circulation port 19 is connected to the combustion section 11 and is located above the first solid material circulation port 18. The synthesis gas discharged from the third gas outlet 32 ​​in the washing and dust removal assembly 3 is used to obtain fly ash slurry. The fly ash circulator 191 is used to burn and gasify the fly ash slurry and then transport it into the combustion section 11.

[0089] The fly ash recirculator 191 aims to further improve the overall carbon utilization and energy efficiency of the process. The syngas leaving the cyclone separator still contains extremely fine dust particles. During the downstream washing process, these dust particles are washed out by the circulating water and enter the washing water. After the dust-laden washing water is discharged from the pressure system, solids undergo sedimentation separation in the water and mechanical liquid-solid separation, such as in a horizontal centrifuge. The separated solids contain 5% to 20% carbon. This carbon is lost as it leaves the gasification unit, which is the primary reason why the carbon conversion rate is less than 100%.

[0090] In this embodiment, the water-containing fly ash slurry separated from the gas washing water is pressurized by a booster pump, and the pressurized slurry at the pump outlet is sent to the fly ash recirculator 191. In the fly ash recirculator 191, a portion of oxygen is also sent to burn and gasify the carbon-containing components in the fly ash, converting almost all the carbon in the solid into gas. The high-temperature flue gas and ash generated by the fly ash recirculator enter the combustion section 11 of the gasifier and mix with the gas-solid flow coming from the lower part of the combustion section 11. By adjusting the oxygen flow rate, the outlet temperature of the fly ash recirculator is controlled to be relatively high. After the fine dust burns, it reaches its softening point but does not completely melt. At this point, the particles agglomerate to produce larger particles. After mixing with the large circulating solids, the larger particles no longer leave the secondary cyclone dust collector in the form of fly ash. In this way, the fly ash from the previous cycle is collected into the circulating solids and finally discharged from the gasifier in the form of coarse ash. The ultimate goal of setting up the fly ash recirculator is to minimize the generation of fly ash in the entire gasifier production process and maximize the carbon conversion utilization rate, such as 99% or higher, even approaching 100%.

[0091] In some embodiments, the raw materials used in the low-calorific-value raw material gasification device 100 include at least one of coal raw materials and biomass raw materials. The coal raw materials have a particle size of less than 2 mm and a moisture content of less than or equal to 30%. The biomass raw materials are formed by compression granulation. The particle size of the biomass raw materials is 5 mm to 20 mm and the moisture content is less than or equal to 35%. When biomass raw materials are used, the temperature inside the furnace body 1 is 650 degrees Celsius to 950 degrees Celsius. When coal raw materials are used, the temperature inside the furnace body 1 is 850 degrees Celsius to 1200 degrees Celsius.

[0092] The particle size of the circulating solid 27 is 45 micrometers to 1000 micrometers. The apparent velocity of the fluid in the combustion section 11 is 3 m / s to 8 m / s, and the apparent velocity of the fluid in the gasification section 12 is 5 m / s to 10 m / s. The pressure of the furnace body 1 is 1 MPa to 6 MPa.

[0093] The ratio of the flow rate of the circulating solid material 27 fed into the furnace body 1 through the first solid material circulation port 18 to the flow rate of the newly added raw material into the furnace body 1 is 50 to 100. Thus, the circulating solid material 27 acts as a large heat storage pool, which facilitates the rapid heating of the newly added raw material after the circulating solid material 27 carries it in, thereby improving the efficiency and effect of gasification.

[0094] This embodiment, through the setting of the above process parameters, makes the operation of the entire gasification equipment more stable, realizes the separation and circulation of circulating solid material 27, realizes the gasification process of low calorific value raw materials, has a high gasification conversion rate, high energy utilization rate, and can realize large-scale industrial application.

[0095] The present invention provides a method for gasifying low-calorific-value raw materials, wherein the gasification operation of the raw materials is performed using the low-calorific-value raw material gasification device 100 of any of the above embodiments.

[0096] In the initial stage of operation of the low-calorific-value feed gasification unit 100, granular material is added to the centrifugal separation component 2 as circulating solid material 27. The added granular material can be b) small particles of quartz sand or kaolinite, with an average particle size of about 100 μm; after normal operation, the circulating solid is the coarse ash particles brought in by the gasification feed.

[0097] When the feedstock fed into the low-calorific-value feedstock gasification unit 100 is biomass, aluminum-containing inorganic additives are added to the furnace body 1. These aluminum-containing inorganic additives can be kaolin powder, bauxite, coal slime, high-alumina slag, finely ground coal slag, etc.

[0098] Example: A semi-industrial pilot plant has been built and extensive operational tests have been completed. The plant is nearly 50 meters high, with a biomass processing capacity of 100 tons / day (or a coal processing capacity of 50 tons / day), a design pressure of 4.0 MPa, and an operating temperature of 750~1150 degrees Celsius. Multiple tests have been conducted on various biomass (including cow dung, wheat straw, and sand willow) and low-calorific-value coal (such as lignite and long-flame coal). For example, in northern regions where cattle farming is concentrated, the accumulation of cow dung has become an environmental problem. The ash content of cow dung can fluctuate between 20% and 60% depending on the feed, season, and source, and its calorific value ranges from 1500 to 2500 kcal / kg. Existing gasifiers struggle to gasify cow dung, or are even incapable of doing so. However, the gasifier device invented in this patent has undergone over a year of testing, demonstrating its ability to effectively gasify shaped biomass cow dung pellets into high-quality syngas. The typical composition of the resulting gas is 25% CO, 35% H2, 10% CH4, 27% CO2, and 2% C2+, and it contains no tar. The overall carbon conversion rate is over 98%. This technology allows for the utilization and conversion of low-calorific-value biomass such as cow dung, increasing its value. To date, no other gasification technology has achieved such results.

[0099] The low-calorific-value feedstock gasification method of this invention employs a large-scale circulating solid powder technology composed of fine-particle ash (particle size ranging from 50 to 500 μm, with an average particle size between 90 and 200 μm). A large, continuously flowing circulating solid regenerative heat storage tank with a certain solid content is formed within the gasification device and controlled to maintain a selected constant temperature. All solid particles in the circulating solid regenerative heat storage tank maintain a rapid flow state within a single loop (the circulating solid regenerative heat storage tank is highly advantageous for low-calorific-value feedstocks; after the feedstock solids are added, they are rapidly heated, ignited, and the combustion and reaction are stable by the large amount of surrounding hot solids). The solid circulation volume is 50 to 100 times the feed volume.

[0100] The gasification process requires a gasification reactant, including oxygen, air, and water vapor or carbon dioxide. The gasification reactant enters the combustion section 11 of the gasification device, flowing rapidly (apparent velocity of 5 m / s to 8 m / s), carrying fine particles with it. During this flow, the oxygen in the gasification reacts with residual carbon from the circulating solids in the first circulation pipe 41, producing carbon dioxide gas. This exothermic combustion reaction heats the circulating solids. The heated circulating solids are then carried upwards by the gas (water vapor and carbon dioxide) into the gasification section 12. In the gasification section 12, fresh feedstock is added to the rapidly flowing hot solids. The feedstock mixes with the circulating solids, and the feedstock particles are rapidly heated by the surrounding hot particles. They then react rapidly (drying and pyrolysis) and undergo semi-coke conversion in the atmosphere of the gasification reactant (water vapor and carbon dioxide), ultimately producing syngas containing H2, CO, CH4, CO2, etc. When biomass is gasified, larger molecules such as C2H4 and C2H6 may also be present. When the gas-solid mixture reaches the top of the gasification section 12, most of the gasification reaction has been completed, with only a small amount of residual carbon mixed in the circulating solids. The gas and solid stream leaving the gasification section 12 enters the centrifugal separation component 2 and the dust removal component 3. The separated solids remain in the circulation loop to continue circulating, while the gas leaves the circulation loop and the reactor after being separated from the solids and enters the downstream system.

[0101] Large particles of solid ash brought in with the raw materials are added to the solid circulation stream. Excess solid particles are discharged based on the material level measurement and controlled ash discharge. In the circuit, except for the combustion section 11 and gasification section 12 which are entrained by the gasifying agent and syngas, the separated solids fully utilize the gravity characteristics of solids to achieve natural circulation, reducing and avoiding the need for fluidizing gas in general gasifiers.

[0102] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to 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 this invention.

[0103] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0104] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0105] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0106] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0107] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A low-calorific-value feedstock gasification device, characterized in that, include: The furnace body includes a combustion section and a gasification section located above the combustion section. The upper part of the furnace body has a first gas outlet connected to the gasification section, and the lower part of the furnace body has a first solid material circulation port connected to the combustion section. A centrifugal separation component has a first feed inlet, a second air outlet, and a first discharge outlet. The first feed inlet is connected to the first air outlet. After the fluid discharged from the first air outlet flows into the centrifugal separation component, gas and solid phases separate to obtain a gas phase flow and a solid phase flow. The solid phase flow can settle and accumulate in the centrifugal separation component and form a circulating solid material. The first discharge outlet is connected to the first solid material circulation port of the furnace body. The dust removal component has a second feed inlet, a third air outlet, and a second discharge outlet. The second feed inlet of the dust removal component is connected to the second air outlet. The gas phase flow in the centrifugal separation component can enter the dust removal component through the second air outlet. The synthesis gas after dust removal by the dust removal component is discharged through the third air outlet. The second discharge outlet is connected to the first solid material circulation port of the centrifugal separation component or the furnace body, so that the powder separated in the dust removal component can be transported into the centrifugal separation component or the furnace body through the second discharge outlet.

2. The low-calorific-value feedstock gasification device according to claim 1, characterized in that, The centrifugal separation assembly includes a centrifugal tube and a circulating material leg. The centrifugal tube is arc-shaped. The first end of the centrifugal tube is configured as the first feed inlet. The second end of the centrifugal tube is connected to the upper part of the circulating material leg. The second air outlet is located at the upper part of the circulating material leg. The second air outlet and the second end of the centrifugal tube are spaced apart in the circumferential direction of the circulating material leg. The first discharge port is located at the lower part of the circulating material leg. The fluid discharged from the first outlet flows into the centrifuge tube and undergoes gas-solid two-phase separation to obtain a gas phase flow and a solid phase flow. The circulating material leg has a material cavity, and the upper part of the material cavity is constructed as an inertial separation section so that the solid phase flow can settle and accumulate in the material cavity and form the circulating solid material.

3. The low-calorific-value feedstock gasification device according to claim 2, characterized in that, The material chamber of the circulating material leg extends vertically, and the angle between the airflow direction at the second end of the centrifuge tube and the vertical direction is less than the first threshold.

4. The low-calorific-value feedstock gasification device according to claim 3, characterized in that, The second end of the centrifuge tube is disposed adjacent to the first side of the circulating material leg, and the solid phase flow discharged from the second end of the centrifuge tube is closer to the inner wall surface of the first side of the circulating material leg than the gas phase flow.

5. The low-calorific-value feedstock gasification device according to claim 2, characterized in that, The second air outlet and the second end of the centrifuge tube are respectively located on opposite sides of the circulating material leg in the circumferential direction; And / or, in the projection along the axial direction of the circulating material leg, the second air outlet and the centrifuge tube are misaligned; And / or, the centrifuge tube is an arc-shaped tube, and the central angle between the first end and the second end of the centrifuge tube is greater than or equal to 90 degrees and less than or equal to 180 degrees.

6. The low-calorific-value feedstock gasification device according to claim 1, characterized in that, The dust removal component is a cyclone separator, which includes a cylinder. The second feed inlet, the third air outlet, and the second discharge outlet are located on the cylinder. The second feed inlet on the cylinder is connected to the second air outlet on the centrifugal separation component through a guide pipe. The guide pipe is connected to the cylinder but not tangent to it. The cylinder is provided with an inner liner, and a guide block is provided at one end of the inner cavity of the guide tube adjacent to the cylinder. The guide block is used to guide the gas phase flow in the guide tube to enter the inner cavity of the inner liner along the tangential direction of the inner cavity of the inner liner.

7. The low-calorific-value feedstock gasification device according to claim 6, characterized in that, The inner liner is coaxially sleeved with the cylinder, or the inner liner is offset relative to the cylinder; And / or, in the projection of the cylinder along its axial direction, the axis of the guide tube intersects the axes of the cylinder and the inner liner, or the axis of the guide tube is offset relative to the axis of at least one of the cylinder and the inner liner.

8. The low-calorific-value feedstock gasification device according to claim 1, characterized in that, It also includes a first circulation pipe and a second circulation pipe. The first circulation pipe is located between the first feed inlet of the centrifugal separation component and the first solid material circulation inlet of the furnace body. The centrifugal separation component has a second solid material circulation inlet, and the second circulation pipe is located between the second feed inlet of the dust removal component and the second solid material circulation inlet of the centrifugal separation component. The first discharge port is higher in the vertical direction than the first solid material circulation port, the second discharge port is higher in the vertical direction than the second solid material circulation port, the angle between the axis of the first circulation pipe and the horizontal plane is greater than or equal to 45 degrees, and the angle between the axis of the second circulation pipe and the horizontal plane is greater than or equal to 45 degrees.

9. The low-calorific-value feedstock gasification device according to claim 8, characterized in that, Both the first discharge port and the second solid material circulation port are located below the surface of the circulating solid material in the centrifugal separation component in the vertical direction, and the height of the second solid material circulation port in the vertical direction is higher than the height of the first discharge port. And / or, the angle between the axis of the first circulation tube and the horizontal plane is greater than or equal to 50 degrees and less than or equal to 60 degrees, and the angle between the axis of the second circulation tube and the horizontal plane is greater than or equal to 50 degrees and less than or equal to 60 degrees.

10. The low-calorific-value feedstock gasification apparatus according to any one of claims 1 to 9, characterized in that, The furnace body includes multiple feeding ports, which are connected to the gasification section. Some of the feeding ports are at a higher height in the vertical direction than other parts of the feeding ports.

11. The low-calorific-value feedstock gasification apparatus according to any one of claims 1 to 9, characterized in that, The furnace body includes multiple gasifying agent inlets, all of which are connected to the combustion section. These gasifying agent inlets are divided into multiple gasifying agent inlet groups, each group including at least one gasifying agent inlet. The gasifying agent inlet groups are arranged at intervals along the axial direction of the combustion section. When a gasifying agent inlet group includes multiple gasifying agent inlets, the gasifying agent inlets within the same group are arranged at intervals along the circumferential direction of the combustion section. At least part of the gasifying agent inlet is located below the first solid material circulation port, and the gas flow direction of the gasifying agent inlet is inclined upward.

12. The low-calorific-value feedstock gasification apparatus according to any one of claims 1 to 9, characterized in that, The furnace body includes a first ash discharge port and a second ash discharge port. The first ash discharge port is located at one end of the combustion section adjacent to the gasification section, and the second ash discharge port is located at the bottom of the furnace body.

13. The low-calorific-value feedstock gasification apparatus according to any one of claims 1 to 9, characterized in that, The furnace body includes a fly ash circulation port, and a fly ash circulator is provided at the fly ash circulation port. The fly ash circulation port is connected to the combustion section and located above the first solid material circulation port. The syngas discharged from the third gas outlet of the dust removal component is washed to obtain fly ash slurry. The fly ash circulator is used to burn and gasify the fly ash slurry and then transport it into the combustion section.

14. The low-calorific-value feedstock gasification device according to claim 1, characterized in that, The low-calorific-value feedstock gasification device uses at least one of coal and biomass feedstock. The coal feedstock has a particle size of less than 2 mm and a moisture content of less than or equal to 30%. The biomass feedstock is formed by compression granulation. The biomass feedstock has a particle size of 5 mm to 20 mm and a moisture content of less than or equal to 35%. When using biomass feedstock, the temperature inside the furnace body is 650 degrees Celsius to 950 degrees Celsius. When using coal feedstock, the temperature inside the furnace body is 850 degrees Celsius to 1200 degrees Celsius. And / or, the particle size of the recycled solids is from 45 micrometers to 1000 micrometers; And / or, the apparent velocity of the fluid in the combustion section is 3 m / s to 8 m / s, and the apparent velocity of the fluid in the gasification section is 5 m / s to 10 m / s; And / or, the pressure of the furnace body is 1 MPa to 6 MPa; And / or, the ratio of the flow rate of the circulating solid material delivered into the furnace body from the first solid material circulation port to the flow rate of the raw material newly added into the furnace body is 50 to 100.

15. A method for gasifying low-calorific-value feedstock, characterized in that, The gasification of raw materials is carried out using the low-calorific-value raw material gasification device as described in any one of claims 1 to 14.

16. The method for gasifying low-calorific-value feedstocks according to claim 15, characterized in that, In the initial stage of operation of the low-calorific-value raw material gasification device, granular material is added to the centrifugal separation component as circulating solid material. And / or, when the feedstock fed into the low-calorific-value feedstock gasification device is biomass feedstock, aluminum-containing inorganic additives are added to the furnace body.

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