Device and method for preparing synthesis gas by coupling biomass gasification with high-temperature thermal reforming

Abstract

The invention belongs to the technical field of biomass energy chemical industry, and particularly relates to a device and a method for preparing synthesis gas by coupling biomass gasification with high-temperature thermal reforming, and the device for preparing synthesis gas by coupling biomass gasification with high-temperature thermal reforming comprises a multi-section graded fluidized bed gasification furnace, the middle part of a furnace body of the multi-section grading fluidized bed gasification furnace is of a conical barrel-shaped structure, the upper part and the lower part of the furnace body of the multi-section grading fluidized bed gasification furnace are of cylindrical barrel-shaped structures, and the multi-section grading fluidized bed gasification furnace is connected with a high-temperature reforming furnace through a long pipeline; according to the device, the multi-section grading fluidized bed, the agglomerated ash separation component and the high-temperature reforming furnace are coupled, the carbon conversion rate of the device can reach 95% or above, tar and methane can be effectively cracked, and the tar content in synthesis gas is lower than 20 mg / Nm.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of biomass energy and chemical industry, and particularly relates to a device and method for preparing synthesis gas by coupling biomass gasification with high-temperature thermal reforming. BACKGROUND

[0002] Biomass gasification technology is a key approach to convert biomass into synthesis gas (mainly composed of CO and H2), which can be used as an important raw material for producing clean fuel, high-value-added chemicals and power generation. The currently industrialized gasification technologies mainly include fixed bed, fluidized bed and entrained flow bed. The fixed bed gasifier is simple in structure and easy to operate, but it has poor adaptability to raw materials, is only suitable for processing blocky biomass, has limited processing scale, and the synthesis gas produced has high content of tar and methane, which can easily cause blockage of downstream pipelines and equipment and make wastewater treatment difficult. The fluidized bed gasifier has good adaptability to raw materials and mass and heat transfer performance, and can process powdery or small-particle biomass with high gasification efficiency, but it still has problems such as low carbon conversion rate (usually less than 90%), high carbon content in fly ash, and incomplete conversion of tar and methane in synthesis gas, which limits its application in high-end chemical synthesis. The entrained flow bed gasifier has high operating temperature (usually > 1300℃), clean synthesis gas with very low content of tar and methane, and carbon conversion rate of more than 98%, but it has strict requirements on the particle size of raw materials, which needs to be crushed to microns, resulting in high energy consumption and cost for pretreatment. In addition, the high-alkali biomass ash is easy to cause slagging and corrosion of the furnace wall at high temperature, affecting the long-term stable operation.

[0003] In order to integrate the advantages of various gasification technologies and make up for the shortcomings of single process, in recent years, various two-stage or multi-stage coupled gasification methods have appeared. For example, patent CN201210144562A proposes a two-stage gasification process suitable for fuels with wide particle size distribution, which combines a fluidized bed pyrolyzer with an entrained flow bed gasifier to separate pyrolysis and gasification, thereby reducing tar generation to some extent. However, this process is still not ideal in terms of ash separation and carbon conversion efficiency. Patent CN202422612529U discloses a biomass gasification system coupling fluidized bed and entrained flow bed, which has the advantages of strong adaptability of fluidized bed to raw materials and high quality of synthesis gas of entrained flow bed, but the system has many units and complex process, resulting in high overall energy consumption, and there is still room for optimization in fly ash circulation, slag water treatment, etc. SUMMARY

[0004] The present application provides a device and method for preparing synthesis gas by coupling biomass gasification with high-temperature thermal reforming, aiming at the problems of low carbon conversion efficiency, incomplete tar control and high system energy consumption of the existing biomass gasification devices.

[0005] To achieve the above purpose, the present application adopts the following technical scheme: The utility model provides a kind of biomass gasification coupling high-temperature thermal reforming device for synthetic gas, including multistage staged fluidized bed gasification furnace, the middle part of the furnace body of the multistage staged fluidized bed gasification furnace is set as conical cylinder structure, the upper portion and lower portion of the furnace body of the multistage staged fluidized bed gasification furnace are set as cylindrical cylinder structure, the multistage staged fluidized bed gasification furnace is divided into dilute phase zone and dense phase zone by middle conical cylinder, biomass feeding port is provided on the side wall of the lower portion of the multistage staged fluidized bed gasification furnace, a group of secondary gasification agent import is opened in the upper portion of the multistage staged fluidized bed gasification furnace, conical distribution plate is fixedly installed on the inner wall of the lower portion of the multistage staged fluidized bed gasification furnace, a plurality of through holes are provided on the conical distribution plate, distribution plate gasification agent inlet pipe is fixedly installed at the lower end of the multistage staged fluidized bed gasification furnace, one end of the distribution plate gasification agent inlet pipe extends to the inside of the multistage staged fluidized bed gasification furnace, the multistage staged fluidized bed gasification furnace is connected with high-temperature reforming furnace by long pipeline, and the lower end of the multistage staged fluidized bed gasification furnace is provided with melt-agglomerated ash separation component.

[0006] Further, the high-temperature reforming furnace is set as vertical cylindrical structure, the upper end of the high-temperature reforming furnace is provided with gas flow bed burner, one end of the gas flow bed burner extends to the inside of the high-temperature reforming furnace, the upper end of the gas flow bed burner is provided with oxygen inlet, the upper portion of the gas flow bed burner is symmetrically provided with circulating cooling water inlet and circulating cooling water outlet, the side wall of the upper portion of the high-temperature reforming furnace is connected with dilute phase zone by long pipeline, the middle portion of the high-temperature reforming furnace is provided with a pair of secondary oxygen gas inlet, the lower portion of the high-temperature reforming furnace is symmetrically provided with spray water inlet and synthetic gas outlet, the lower end of the high-temperature reforming furnace is provided with gas flow bed slagging port, and the height difference between the secondary oxygen gas inlet and the top of the high-temperature reforming furnace is 1 / 3-1 / 2 of the high-temperature reforming furnace.

[0007] Further, the melt-agglomerated ash separation component includes annular separation pipe, one end of the annular separation pipe extends to the inside of the fluidized bed gasification furnace, the other end of the annular separation pipe is connected with ash falling pipe through flange, the lower end of the conical distribution plate is fixedly installed on the upper end of the annular separation pipe, central jet pipe is arranged at the central position in the annular separation pipe, the outlet end of the central jet pipe is arranged on the side wall of the annular separation pipe, the lower end of the ash falling pipe is provided with fluidized bed slagging port, and annular separation pipe gasification agent inlet pipe is fixedly installed on the middle portion of the ash falling pipe.

[0008] Further, the included angle α between the conical generatrix of the upper conical cylinder structure of the multistage staged fluidized bed gasification furnace and the central axis is 1-20°.

[0009] Further, the height between the secondary gasification agent import and the biomass feeding port is 1 / 3-1 / 2 of the height of the multistage staged fluidized bed gasification furnace.

[0010] Furthermore, the cone distribution plate has an opening ratio of 0.5%-2%, a hole diameter of 2-6mm, and an angle β between the generatrix of the cone and the central axis of 20-50°.

[0011] A method for producing syngas from biomass through gasification coupled with high-temperature thermal reforming includes the following steps: First, the biomass is pretreated by sieving it to a particle size of 1-10 mm. Second, the pretreated biomass is fed into a multi-stage classifying fluidized bed gasifier through the biomass inlet. Gasifying agent is introduced through the gasifier inlet pipes of the distribution plate, the central jet pipe, and the annular separator pipe, and also through the secondary gasifier inlet located in the dilute phase zone, maintaining the overall temperature inside the furnace at 600-800℃. Then, the gas-solid mixture generated by the multi-stage classifying fluidized bed gasifier is separated by a fused agglomerate ash separation component. Solid ash enters the ash discharge pipe through the annular separation pipe and is then discharged through the fluidized bed slag discharge port. Finally, the crude syngas entering the high-temperature reformer undergoes a deep reforming reaction at 1100-1500℃ with oxygen from the fluidized bed burner and oxygen injected from the upper and middle secondary oxygen inlet. The high-temperature syngas and molten slag flow downwards and are quenched by injecting quench water through the spray water inlet. The syngas is cooled to 700-1000℃, and the molten slag is discharged from the fluidized bed slag discharge port after solidification. The treated syngas is then exported from the syngas outlet.

[0012] Furthermore, the oxygen volume concentrations of the gasifying agent introduced into the gasifying agent inlet pipe of the distribution plate, the central jet pipe, and the annular separation pipe are 10-20%, 30-70%, and 0-20%, respectively, and the oxygen volume concentration of the gasifying agent introduced into the secondary gasifying agent inlet is 30-50%.

[0013] Furthermore, the molar ratio of oxygen injected from the gas flow bed burner to the oxygen required for complete combustion of the crude gasification gas is set to 0.05~0.15, and the molar ratio of oxygen entering from the secondary oxygen inlet to the oxygen required for complete combustion of the crude gasification gas is set to 0.05~0.15.

[0014] Furthermore, the operating pressure of the multi-stage fluidized bed gasifier and the high-temperature reformer is 0.1-3 MPa.

[0015] Compared with the prior art, the present invention has the following advantages: 1. This invention couples a multi-stage graded fluidized bed, a melt-polymer ash separation component, and a high-temperature reformer. The carbon conversion rate of this device can reach over 95%, and it can effectively crack tar and methane, reducing the tar content in the syngas to below 20 mg / Nm³.

[0016] 2. This invention combines the advantages of fluidized bed and airflow bed, optimizing energy utilization.

[0017] 3. The raw materials of this invention are widely applicable and can process a variety of biomass raw materials, such as straw and sawdust, with relatively relaxed requirements on particle size.

[0018] 4. The ash and slag of this invention are discharged dry, resulting in no wastewater pollution. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the present invention; In the figure, 1 is a multi-stage fluidized bed gasifier, 2 is a biomass feed inlet, 3 is a secondary gasifying agent inlet, 4 is a conical distribution plate, 5 is a through hole, 6 is a gasifying agent inlet pipe of the distribution plate, 7 is a long pipe, 8 is a high-temperature reformer, 9 is a fluidized bed burner, 10 is an oxygen inlet, 11 is a circulating cooling water inlet, 12 is a circulating cooling water outlet, 13 is a secondary oxygen inlet, 14 is a spray water inlet, 15 is a syngas outlet, 16 is a fluidized bed slag discharge port, 17 is an annular separation pipe, 18 is an ash collection pipe, 19 is a central jet pipe, 20 is a fluidized bed slag discharge port, and 21 is a gasifying agent inlet pipe of the annular separation pipe. Detailed Implementation

[0020] To further illustrate the technical solution of the present invention, the present invention will be further described below through embodiments.

[0021] like Figure 1As shown, an apparatus for biomass gasification coupled with high-temperature thermal reforming to produce syngas includes a multi-stage staged fluidized bed gasifier 1. The middle part of the furnace body of the multi-stage staged fluidized bed gasifier 1 is configured as a conical structure, while the upper and lower parts of the furnace body are both configured as cylindrical structures. The multi-stage staged fluidized bed gasifier 1 is divided into a dilute phase zone and a dense phase zone by the middle conical section. A biomass inlet 2 is provided on the lower side wall of the multi-stage staged fluidized bed gasifier 1. The area above the biomass inlet 2 is the dilute phase zone, and the area below the biomass inlet 2 is the dense phase zone. A set of secondary gasifying agent inlets 3 is opened at the upper part of the multi-stage staged fluidized bed gasifier 1. The lower part of the multi-stage staged fluidized bed gasifier 1... A conical distribution plate 4 is fixedly installed on the wall, and the conical distribution plate 4 is provided with multiple through holes 5. A distribution plate gasifying agent inlet pipe 6 is fixedly installed at the lower end of the multi-stage fluidized bed gasifier 1. One end of the distribution plate gasifying agent inlet pipe 6 extends into the interior of the multi-stage fluidized bed gasifier 1. The multi-stage fluidized bed gasifier 1 is connected to a high-temperature reformer 8 through a long pipe 7. The high-temperature reformer 8 is configured as a vertical cylindrical structure. A fluidized bed burner 9 is provided at the upper end of the high-temperature reformer 8. One end of the fluidized bed burner 9 extends into the interior of the high-temperature reformer 8. An oxygen inlet 10 is opened at the upper end of the fluidized bed burner 9. A circulating cooling water inlet 11 and a circulating cooling water outlet 1 are symmetrically arranged at the upper part of the fluidized bed burner 9. 2. The upper sidewall of the high-temperature reformer 8 is connected to the dilute phase zone via a long pipe 7. A pair of secondary oxygen inlets 13 are provided in the middle of the high-temperature reformer 8. A spray water inlet 14 and a syngas outlet 15 are symmetrically arranged at the lower part of the high-temperature reformer 8. A fluidized bed slag discharge port 16 is provided at the lower end of the high-temperature reformer 8. The height difference between the secondary oxygen inlet 13 and the top of the high-temperature reformer 8 is 1 / 3 to 1 / 2 of the height of the high-temperature reformer 8. A molten agglomerate ash separation component is provided at the lower end of the multi-stage staged fluidized bed gasifier 1. The molten agglomerate ash separation component includes an annular separation pipe 17. One end of the annular separation pipe 17 extends into the interior of the multi-stage staged fluidized bed gasifier 1, and the other end of the annular separation pipe 17 is connected to an ash discharge port via a flange. The lower end of the conical distribution plate 4 is fixedly installed on the upper end of the annular separation pipe 17. A central jet pipe 19 is provided at the center of the annular separation pipe 17, and the outlet end of the central jet pipe 19 is located on the side wall of the annular separation pipe 17. A fluidized bed slag discharge port 20 is provided at the lower end of the ash discharge pipe 18. The gasifying agent inlet pipe of the annular separation pipe 17 is fixedly installed in the middle of the ash discharge pipe 18. The angle α between the generatrix of the upper conical structure of the multi-stage graded fluidized bed gasifier 1 and the central axis is set to 1-20°. The height between the secondary gasifying agent inlet 3 and the biomass feed inlet 2 is 1 / 3 to 1 / 2 of the height of the multi-stage graded fluidized bed gasifier 1. The opening ratio of the conical distribution plate 4 is 0.The pressure is 5%-2%, the aperture is 2-6mm, the angle β between the generatrix of the cone and the central axis is 20-50°, and the operating pressure of the multi-stage fluidized bed gasifier 1 and the high-temperature reformer 8 is 0.1-3MPa. Example

[0022] A method for producing syngas from biomass through gasification coupled with high-temperature thermal reforming includes the following steps: First, the biomass, specifically corn stalks, is pretreated by sieving it to a particle size of 1-10 mm. Second, the pretreated corn stalks are fed into the multi-stage graded fluidized bed gasifier 1 through the biomass inlet 2. Gasifying agent is introduced through the gasifying agent inlet pipe 6 on the distribution plate, the central jet pipe 19, and the annular separation pipe 17. Gasifying agent is also introduced through the secondary gasifying agent inlet 3 located in the dilute phase zone, maintaining the overall temperature within the furnace at 750±20℃. Then, the gas-solid mixture generated by the multi-stage graded fluidized bed gasifier 1 passes through the fused ash separation section. The solid ash is separated and enters the ash discharge pipe 18 through the annular separation pipe 7, and then is discharged through the fluidized bed slag discharge port 20. Finally, the crude syngas entering the high-temperature reformer 8, together with the oxygen entering from the fluidized bed burner 9 and the oxygen injected from the upper and middle secondary oxygen inlet 13, undergoes a deep reforming reaction at 1300°C. The high-temperature syngas and molten slag flow downward and are quenched by injecting quench water through the spray water inlet 14. The syngas is cooled to 900°C, and the molten slag is discharged from the fluidized bed slag discharge port 16 after solidification. The treated syngas is then discharged from the syngas outlet 15.

[0023] An oxygen-water vapor mixture with an oxygen concentration of 15% is introduced through the gasifying agent inlet pipe 6 of the distribution plate, an oxygen-water vapor mixture with an oxygen concentration of 40% is introduced through the central jet pipe 19, and an oxygen-water vapor mixture with an oxygen concentration of 15% is introduced through the gasifying agent inlet pipe 21 of the annular separator pipe; an oxygen-water vapor mixture with an oxygen concentration of 40% is introduced through the secondary gasifying agent inlet 3; the molar ratio of oxygen injected from the fluidized bed burner 9 to the oxygen required for complete combustion of the crude gasified gas is 0.1, and a deep reforming reaction occurs at 1300°C; the molar ratio of oxygen entering from the secondary oxygen inlet 13 to the oxygen required for complete combustion of the crude gasified gas is 0.07.

[0024] The carbon conversion rate of this embodiment reached 96% after testing. The tar content in the outlet syngas (15) was 18 mg / Nm³. The composition of the syngas was: H2: 35.2%, CO: 39.8%, CO2: 19.5%, CH4: 0.4%. Example

[0025] First, the biomass, specifically wood chips, is pretreated by sieving to a particle size of 1-10 mm. Second, the pretreated wood chips are fed into the multi-stage graded fluidized bed gasifier 1 through the biomass inlet 2. Gasifying agent is introduced through the gasifying agent inlet pipes 6 (distribution plate), 19 (central jet pipe), and 17 (annular separation pipe), and also through the secondary gasifying agent inlet 3 (located in the dilute phase zone), maintaining the overall temperature within the furnace at 700±20℃. Finally, the gas-solid mixture generated in the multi-stage graded fluidized bed gasifier 1 is separated by a fused agglomerate ash separation component. The separated solid ash enters the ash discharge pipe 18 through the annular separation pipe 7, and is then discharged through the fluidized bed slag discharge port 20. Finally, the crude syngas entering the high-temperature reformer 8, together with the oxygen entering from the fluidized bed burner 9 and the oxygen injected from the upper and middle secondary oxygen inlet 13, undergoes a deep reforming reaction at 1350°C. The high-temperature syngas and molten slag flow downwards and are quenched by injecting quench water through the spray water inlet 14. The syngas is cooled to 850°C, and the molten slag is discharged from the fluidized bed slag discharge port 16 after solidification. The treated syngas is then discharged from the syngas outlet 15.

[0026] An oxygen-water vapor mixture with an oxygen concentration of 20% is introduced through the gasifying agent inlet pipe 6 of the distribution plate, an oxygen-water vapor mixture with an oxygen concentration of 30% is introduced through the central jet pipe 19, and an oxygen-water vapor mixture with an oxygen concentration of 20% is introduced through the gasifying agent inlet pipe 21 of the annular separation pipe; an oxygen-water vapor mixture with an oxygen concentration of 50% is introduced through the secondary gasifying agent inlet 3; the molar ratio of oxygen injected from the fluidized bed burner 9 to the oxygen required for complete combustion of the crude gasified gas is 0.13, and a deep reforming reaction occurs at 1350°C; the molar ratio of oxygen entering from the secondary oxygen inlet 13 to the oxygen required for complete combustion of the crude gasified gas is 0.09.

[0027] According to the test, the carbon conversion rate of this embodiment is 95.8%, the tar content in the syngas at the outlet of the fluidized bed is 13 mg / Nm³, and the composition of the syngas is: H2: 37.6%, CO: 41.9%, CO2: 17.8%, CH4: 0.2%. Example

[0028] First, the biomass, specifically rice husks, is pretreated by sieving it to a particle size of 1-10 mm. Second, the pretreated rice husks are fed into the multi-stage graded fluidized bed gasifier 1 through the biomass inlet 2. Gasifying agent is introduced through the gasifying agent inlet pipe 6 on the distribution plate, the central jet pipe 19, and the annular separation pipe 17. Gasifying agent is also introduced through the secondary gasifying agent inlet 3 located in the dilute phase zone, maintaining the overall temperature inside the furnace at 800±20℃. Then, the gas-solid mixture generated by the multi-stage graded fluidized bed gasifier 1 is separated by a fused ash separation component. The separated solid ash is then separated through the annular separation pipe. 7. The ash enters the ash discharge pipe 18 and is then discharged through the fluidized bed slag discharge port 20. Finally, the crude syngas entering the high-temperature reformer 8, together with the oxygen entering from the fluidized bed burner 9 and the oxygen injected from the upper and middle secondary oxygen inlet 13, undergoes a deep reforming reaction at 1400°C. The high-temperature syngas and molten slag flow downwards and are quenched by injecting chilled water through the spray water inlet 14. The syngas is cooled to 900°C, and the molten slag is discharged from the fluidized bed slag discharge port 16 after solidification. The treated syngas is then discharged from the syngas outlet 15. The working pressure of the multi-stage fluidized bed gasifier 1 and the high-temperature reformer 8 is 1.5 MPa.

[0029] An oxygen-water vapor mixture with an oxygen concentration of 20% is introduced through the gasifying agent inlet pipe 6 of the distribution plate, an oxygen-water vapor mixture with an oxygen concentration of 50% is introduced through the central jet pipe 19, and an oxygen-water vapor mixture with an oxygen concentration of 20% is introduced through the gasifying agent inlet pipe 21 of the annular separator pipe; an oxygen-water vapor mixture with an oxygen concentration of 50% is introduced through the secondary gasifying agent inlet 3; the molar ratio of oxygen injected from the fluidized bed burner 9 to the oxygen required for complete combustion of the crude gasified gas is 0.1, and a deep reforming reaction occurs at 1400°C; the molar ratio of oxygen entering from the secondary oxygen inlet 13 to the oxygen required for complete combustion of the crude gasified gas is 0.13.

[0030] According to the test, the carbon conversion rate of this embodiment is 95.8%, the tar content in the syngas at the outlet of the fluidized bed is 13 mg / Nm³, and the composition of the syngas is: H2: 35.8%, CO: 40.7%, CO2: 21.1%, CH4: 0.1%. Example

[0031] First, the biomass, specifically wood chips, is pretreated by sieving to a particle size of 1-10 mm. Second, the pretreated wood chips are fed into the multi-stage graded fluidized bed gasifier 1 through the biomass inlet 2. Gasifying agent is introduced through the gasifying agent inlet pipe 6 on the distribution plate, the central jet pipe 19, and the annular separation pipe 17. Gasifying agent is also introduced through the secondary gasifying agent inlet 3 located in the dilute phase zone, maintaining the overall temperature within the furnace at 780±20℃. Then, the gas-solid mixture generated by the multi-stage graded fluidized bed gasifier 1 is separated by a fused ash separation component. The separated solid ash is then separated by an annular separation component. The gas enters the ash discharge pipe 18 through the ash discharge pipe 7 and is then discharged through the fluidized bed slag discharge port 20. Finally, the crude syngas entering the high-temperature reformer 8, together with the oxygen entering from the fluidized bed burner 9 and the oxygen injected from the upper middle secondary oxygen inlet 13, undergoes a deep reforming reaction at 1400°C. The high-temperature syngas and molten slag flow downwards and are quenched by injecting quench water through the spray water inlet 14. The syngas is cooled to 950°C, and the molten slag is discharged from the fluidized bed slag discharge port 16 after solidification. The treated syngas is then discharged from the syngas outlet 15. The working pressure of the multi-stage fluidized bed gasifier 1 and the high-temperature reformer 8 is atmospheric pressure.

[0032] Air is introduced through the gasifying agent inlet pipe 6 of the distribution plate, the central jet pipe 19, and the gasifying agent inlet pipe 21 of the annular separation pipe. The molar ratio of oxygen injected from the gas flow bed burner 9 to the oxygen required for the complete combustion of the crude gasified gas is 0.1, and a deep reforming reaction occurs at 1400°C. The molar ratio of oxygen entering from the secondary oxygen inlet 13 to the oxygen required for the complete combustion of the crude gasified gas is also 0.1.

[0033] According to the test, the carbon conversion rate of this embodiment is 95.5%, the tar content in the syngas at the outlet of the fluidized bed is 12 mg / Nm³, and the composition of the syngas is: H2: 12.3%, CO: 19.8%, CO2: 18.0%, CH4: 0.1%, N2: 49.8%.

[0034] The foregoing has shown and described the main features and advantages of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0035] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A device for producing syngas by coupling biomass gasification with high-temperature thermal reforming, characterized in that: The system includes a multi-stage fluidized bed gasifier (1), wherein the middle part of the gasifier body is configured as a conical structure, and the upper and lower parts of the gasifier body are configured as cylindrical structures. The gasifier body is divided into a dilute phase zone and a dense phase zone by the central conical structure. A biomass feed inlet (2) is provided on the lower side wall of the gasifier body. A set of secondary gasifying agent inlets (3) is provided at the upper part of the gasifier body. A conical distribution plate (4) is fixedly installed on the lower inner wall of the multi-stage fluidized bed gasifier (1). The conical distribution plate (4) is provided with multiple through holes (5). A distribution plate gasifying agent inlet pipe (6) is fixedly installed at the lower end of the multi-stage fluidized bed gasifier (1). One end of the distribution plate gasifying agent inlet pipe (6) extends into the interior of the multi-stage fluidized bed gasifier (1). The multi-stage fluidized bed gasifier (1) is connected to a high-temperature reformer (8) through a long pipe (7). A molten agglomerate ash separation component is provided at the lower end of the multi-stage fluidized bed gasifier (1).

2. The apparatus for producing syngas by coupling biomass gasification with high-temperature thermal reforming according to claim 1, characterized in that: The high-temperature reformer (8) is configured as a vertical cylindrical structure. A fluidized bed burner (9) is provided at the upper end of the high-temperature reformer (8). One end of the fluidized bed burner (9) extends into the interior of the high-temperature reformer (8). An oxygen inlet (10) is provided at the upper end of the fluidized bed burner (9). A circulating cooling water inlet (11) and a circulating cooling water outlet (12) are symmetrically arranged at the upper part of the fluidized bed burner (9). The dilute phase zone is connected to the upper side wall of the high-temperature reformer (8) through a long pipe (7). A pair of secondary oxygen inlets (13) are provided in the middle of the high-temperature reformer (8). A spray water inlet (14) and a syngas outlet (15) are symmetrically arranged at the lower part of the high-temperature reformer (8). A fluidized bed slag discharge port (16) is provided at the lower end of the high-temperature reformer (8). The height difference between the secondary oxygen inlet (13) and the top of the high-temperature reformer (8) is 1 / 3 to 1 / 2 of the height of the high-temperature reformer (8).

3. The apparatus for producing syngas by coupling biomass gasification with high-temperature thermal reforming according to claim 1, characterized in that: The molten agglomerate ash separation component includes an annular separation tube (17), one end of which extends into the interior of a multi-stage graded fluidized bed gasifier (1). The other end of the annular separation tube (17) is connected to an ash discharge pipe (18) via a flange. The lower end of the conical distribution plate (4) is fixedly installed at the upper end of the annular separation tube (17). A central jet pipe (19) is provided at the center of the annular separation tube (17). The outlet end of the central jet pipe (19) is located on the side wall of the annular separation tube (17). A fluidized bed slag discharge port (20) is provided at the lower end of the ash discharge pipe (18). An annular separation tube gasifying agent inlet pipe (21) is fixedly installed in the middle of the ash discharge pipe (18).

4. The apparatus for producing syngas by coupling biomass gasification with high-temperature thermal reforming according to claim 1, characterized in that: The angle α between the generatrix of the upper conical structure of the multi-stage graded fluidized bed gasifier (1) and the central axis is set to 1-20°.

5. The apparatus for producing syngas by coupling biomass gasification with high-temperature thermal reforming according to claim 1, characterized in that: The height between the secondary gasifying agent inlet (3) and the biomass feed inlet (2) is 1 / 3 to 1 / 2 of the height of the multi-stage fluidized bed gasifier (1).

6. The apparatus for producing syngas by coupling biomass gasification with high-temperature thermal reforming according to claim 1, characterized in that: The cone distribution plate (4) has an opening ratio of 0.5%-2%, a hole diameter of 2-6mm, and an angle β between the cone generatrix and the central axis of 20-50°.

7. A method for producing syngas from biomass through gasification coupled with high-temperature thermal reforming as described in any one of claims 2-6, characterized in that, Includes the following steps: First, the biomass is pretreated by sieving it to a particle size of 1-10 mm. Next, the pretreated biomass is added to the multi-stage graded fluidized bed gasifier (1) through the biomass feed inlet (2); gasifying agent is introduced through the gasifying agent inlet pipe (6) of the distribution plate, the central jet pipe (19) and the gasifying agent inlet pipe (21) of the annular separation pipe, and gasifying agent is introduced through the secondary gasifying agent inlet (3) located in the dilute phase zone, so that the overall temperature inside the furnace is controlled at 600-800℃; then, the gas-solid mixture generated by the multi-stage graded fluidized bed gasifier (1) is separated by the fused ash separation component, and the separated solid ash slag enters the ash collection channel through the annular separation pipe (17). The syngas enters the high-temperature reformer (8) and is then discharged through the fluidized bed slag discharge port (20). Finally, the crude syngas entering the high-temperature reformer (8) and the oxygen entering from the fluidized bed burner (9) and the oxygen injected from the upper middle secondary oxygen inlet (13) undergo a deep reforming reaction at 1100-1500℃. The high-temperature syngas and slag flow downwards and are quenched by injecting chilled water through the spray water inlet (14). The syngas is cooled to 700-1000℃. After the slag solidifies, it is discharged from the fluidized bed slag discharge port (16). The treated syngas is then discharged from the syngas outlet (15).

8. The method for producing syngas by biomass gasification coupled with high-temperature thermal reforming according to claim 6, characterized in that: The oxygen volume concentrations of the gasifying agent introduced from the gasifying agent inlet pipe (6) of the distribution plate, the central jet pipe (19) and the gasifying agent inlet pipe (21) of the annular separator are 10-20%, 30-70% and 0-20% respectively, and the oxygen volume concentration of the gasifying agent introduced from the secondary gasifying agent inlet (3) is 30-50%.

9. A method for producing syngas by biomass gasification coupled with high-temperature thermal reforming according to claim 6, characterized in that: The molar ratio of oxygen injected from the gas flow bed burner (9) to the oxygen required for complete combustion of the crude gasification gas is set to 0.05~0.15, and the molar ratio of oxygen entering from the secondary oxygen inlet (13) to the oxygen required for complete combustion of the crude gasification gas is set to 0.05~0.

15.

10. A method for producing syngas by biomass gasification coupled with high-temperature thermal reforming according to claim 6, characterized in that: The working pressure of the multi-stage fluidized bed gasifier (1) and the high-temperature reformer (8) is 0.1-3 MPa.

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