System for synthesizing methanol by using biomass synthesis gas

Abstract

The invention provides a system for synthesizing methanol by using biomass synthesis gas, a plasma generator is integrated in a reactor, and after crude synthesis gas enters, tar is cracked into CO and H2 in situ by high-density active particles generated by discharge of the plasma generator so as to eliminate macromolecular hydrocarbons and prevent the macromolecular hydrocarbons from entering a subsequent pipeline or contacting a catalyst. A plasma cracking area and a first catalyst bed layer are integrated in the same reactor, and then steam inlet is coupled, so that tar is cracked by plasmas, extra CO and H2 are generated, the total amount of effective gas is increased, and dual-reforming reaction collaboration, consumption of excessive CH4 and steam, synchronous conversion of CO2 and directional regulation and control of the H2 / CO ratio in mixed gas are realized; and the H2 / CO ratio in the mixed gas meets the requirement of methanol synthesis. When biomass synthesis gas is used for synthesizing methanol, external hydrogen supplementation is not needed, the system optimizes gas composition in a self-sufficiency mode, and energy consumption is greatly reduced.

Description

Technical Field

[0001] This application relates to the field of organic compounds, and more specifically, to a system for synthesizing methanol from biomass syngas. Background Technology

[0002] Biomass syngas is a mixture of combustible gases, primarily H2 and CO, produced through thermochemical conversion. It typically also contains carbon dioxide (CO2), CH4, and tar. It is an important intermediate product for biomass energy utilization and green chemical engineering, characterized by its renewable and low-carbon emissions.

[0003] However, traditional biomass syngas contains insufficient H2 content. If used directly for methanol synthesis, additional hydrogen must be added or the H2 / CO ratio adjusted through a water-gas shift reaction, leading to increased energy consumption and a more complex process. Furthermore, large molecular hydrocarbons such as tar in biomass syngas can condense at low temperatures, clogging pipelines and covering the active sites on the catalyst surface, resulting in catalyst deactivation. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a system for synthesizing methanol from biomass syngas. A plasma generator is integrated into the reactor. After the crude syngas enters, the high-density active particles generated by the plasma generator decompose the tar in situ into CO and H2, eliminating large molecular hydrocarbons and preventing them from entering subsequent pipelines or contacting the catalyst. Integrating a plasma decomposition zone and a first catalyst bed within the same reactor, coupled with steam injection, not only achieves plasma decomposition of tar to generate additional CO and H2, increasing the total effective gas volume, but also achieves synergistic dual-reaction process, consuming excess CH4 and steam, and simultaneously converting CO2. This allows for targeted control of the H2 / CO ratio in the mixed gas, ensuring the H2 / CO ratio meets the requirements for methanol synthesis. When synthesizing methanol from biomass syngas, no external hydrogen supplementation is required; the system is self-sufficient in optimizing the gas composition, significantly reducing energy consumption.

[0005] To solve the above-mentioned technical problems, the present invention is implemented as follows: In a first aspect, the present invention provides a system for synthesizing methanol from biomass syngas, characterized in that the system comprises: Reactor (1), plasma generator (2), booster pump (3) and methanol synthesis reactor (4); The reactor (1) includes a first air inlet (11), a second air inlet (12) and an air outlet (13). The first air inlet (11) is used to introduce crude biomass syngas, the second air inlet (12) is used to introduce water vapor, and the air outlet (13) is used to discharge the mixed gas. The reactor (1) is connected to the plasma generator (2); the reactor contains a first catalyst. The booster pump (3) includes an inlet end (31) and an outlet end (32). The inlet end (31) is connected to the outlet (13) through a pipeline, and the outlet end (32) is connected to the inlet of the methanol synthesis reactor (4) through a pipeline. The reactor (1) is configured to cause the tar in the crude syngas to crack into CO and H2 under the action of high-density active particles generated by the discharge of the plasma generator, and to promote the CH4 in the crude syngas to undergo a reforming reaction with the water vapor under the action of the first catalyst, converting it into CO and H2; the CO2 in the crude syngas undergoes a dry reforming reaction with the CH4, converting it into CO and H2. The booster pump (3) is configured to pressurize the mixed gas discharged from the reactor (1) to 2.5 MPa-4 MPa; The methanol synthesis reactor (4) is configured to perform a hydrogenation reaction on the pressurized mixed gas under the action of a second catalyst to synthesize methanol.

[0006] Optionally, a separator (33) is provided on the pipeline between the air inlet (31) of the booster pump (3) and the air outlet (13) of the reactor (1); The separator (33) is configured to separate solid ash from the mixed gas.

[0007] Optionally, the plasma generator (2) is located on one side near the first air inlet (11).

[0008] Optionally, the system further includes: Feeding device (5), fluidized bed gasifier (6) and cyclone separator (7); The feeding device (5) is connected to the inlet of the fluidized bed gasifier (6), the outlet of the fluidized bed gasifier (6) is connected to the inlet of the cyclone separator (7), and the outlet of the cyclone separator (7) is connected to the first air inlet (11) of the reactor (1). The feeding device (5) is configured to transport biomass raw materials to the fluidized bed gasifier (6); The fluidized bed gasifier (6) is configured to cause the biomass raw material and the gasifying agent to undergo a gasification reaction at a temperature of 700 ℃-1000 ℃ to generate mixed syngas; The cyclone separator (7) is configured to filter the mixed syngas to obtain the crude biomass syngas.

[0009] Optionally, the fluidized bed gasifier (6) is filled with any one of quartz sand, alumina particles and magnesium oxide particles.

[0010] Optionally, the cyclone separator (7) includes a slag outlet (71); The slag outlet (71) is connected to the inside of the fluidized bed gasifier (6) via a pipe; The cyclone separator (7) is also configured to return the residue remaining after filtering the mixed syngas to the fluidized bed gasifier (6).

[0011] Optionally, the feeding device (5) includes a hopper (51) and a screw feeder (52); The silo (51) includes an inlet (511) and an outlet (512), and the screw feeder (52) is connected to the outlet (512) of the silo (51) and the inlet of the fluidized bed gasifier (6), respectively. The silo (51) is configured to feed and store the biomass raw material through the feed inlet (511) and to discharge the biomass raw material through the discharge outlet (512). The screw feeder (52) is configured to transport the biomass feedstock discharged from the hopper (51) to the fluidized bed gasifier (6).

[0012] Optionally, the hopper (51) includes a first part (513) and a second part (514); The first part (513) is internally connected to the second part (514), and in the target direction, the first part (513) is located above the second part (514); The feed inlet (511) is provided on the side of the first part (513) away from the second part (514), and the discharge outlet (512) is provided on the side of the second part (514) away from the first part (513). The diameter of the second part (514) in the direction perpendicular to the target direction decreases sequentially in the direction toward the first part (513).

[0013] Optionally, the system further includes a first heat exchanger (41), a gas-liquid separator (42), and a liquid storage tank (43); The inlet of the first heat exchanger (41) is connected to the outlet of the methanol synthesis reactor (4), the outlet of the first heat exchanger (41) is connected to the inlet of the gas-liquid separator (42), and the outlet of the gas-liquid separator (42) is connected to the inside of the storage tank (43). The first heat exchanger (41) is configured to exchange heat between the methanol discharged from the methanol synthesis reactor (4) and cooling water to obtain cooled methanol; The gas-liquid separator (42) is configured to separate the cooled methanol to obtain liquid methanol and flue gas; The storage tank (43) is configured to store the liquid methanol.

[0014] Optionally, the system further includes a second heat exchanger (44) and a third heat exchanger (45); The second heat exchanger (44) is connected to the fluidized bed gasifier (6) and the gas outlet of the gas-liquid separator (42), respectively; The third heat exchanger (45) is connected to the reactor (1) and the gas outlet of the gas-liquid separator (42), respectively. The second heat exchanger (44) is configured to supply the gasifying agent to the fluidized bed gasifier (6) and to preheat the gasifying agent using the flue gas discharged from the gas-liquid separator (42); The third heat exchanger (45) is configured to supply steam to the reactor (1) and preheat the steam using the flue gas discharged from the gas-liquid separator (42); The vaporizing agent is air and / or oxygen.

[0015] Beneficial effects: This invention provides a system for synthesizing methanol from biomass syngas. A plasma generator is integrated into the reactor. After the crude syngas enters, the high-density active particles generated by the plasma generator decompose the tar in situ into CO and H2, eliminating large molecular hydrocarbons and preventing them from entering subsequent pipelines or contacting the catalyst. Integrating a plasma decomposition zone and a first catalyst bed within the same reactor, coupled with steam injection, not only achieves plasma decomposition of tar to generate additional CO and H2, increasing the total effective gas volume, but also achieves synergistic dual-reaction process, consuming excess CH4 and steam, and simultaneously converting CO2. It also allows for targeted control of the H2 / CO ratio in the mixed gas, ensuring the H2 / CO ratio meets the requirements for methanol synthesis. When synthesizing methanol from biomass syngas, no external hydrogen supplementation is required; the system is self-sufficient, optimizing the gas composition and significantly reducing energy consumption.

[0016] In the system provided by this invention, plasma pyrolysis, CH4 / CO2 reforming, mixed gas transportation, and methanol synthesis are tightly integrated within the system, eliminating the energy losses associated with traditional multi-unit operations. It eliminates the need for separate tar purification, hydrogen replenishment, and proportioning units, reducing equipment investment and maintenance costs. The system of this invention uses a plasma-catalyst synergistic reactor as its core, constructing a closed-loop process of "impurity removal-proportioning-synthesis," transforming obstacles in traditional technologies into effective resources driving methanol synthesis, and realizing the green, efficient, and large-scale application of biomass-based methanol production.

[0017] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0018] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of a system structure for synthesizing methanol from biomass syngas, as proposed in an embodiment of this application. Figure 2 This is a schematic diagram of another system structure for synthesizing methanol from biomass syngas, as proposed in an embodiment of this application. Figure 3 This is a flowchart of the method for synthesizing methanol from biomass syngas according to an embodiment of this application.

[0019] Explanation of reference numerals in the attached figures: 1. Reactor; 11. First air inlet; 12. Second air inlet; 13. Air outlet; 2. Plasma generator; 3. Booster pump; 31. Air inlet; 32. Air outlet; 33. Separator; 34. Discharge port; 35. Ash collector; 4. Methanol synthesis reactor; 41. First heat exchanger; 42. Gas-liquid separator; 421. First pipeline; 422. First branch pipe; 423. Second branch pipe; 424. Valve; 43. Storage tank; 44. Second heat exchanger; 45. Third heat exchanger; 5. Feeding device; 51. Hopper; 511. Feed inlet; 512. Discharge outlet; 513. First part; 514. Second part; 52. Screw feeder; 6. Fluidized bed gasifier; 7. Cyclone separator; 71. Slag outlet. Detailed Implementation

[0020] The embodiments of this application will now be described in detail. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0021] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise stated, "multiple" means two or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0022] In the description of this application, 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", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0023] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0024] In related technologies, the H2 / CO ratio in the syngas produced by traditional biomass gasification is 0.8-1.5, far lower than the optimal ratio (2.0-2.2) required for methanol synthesis. Therefore, traditional processes rely on the water-gas shift reaction (CO + H2O → CO2 + H2) to supplement hydrogen. However, this reaction requires an iron-chromium catalyst at 200 ℃-400 ℃, which not only increases the energy consumption of the methanol synthesis process but also produces the byproduct CO2, requiring additional separation and increasing system complexity.

[0025] This invention's embodiments reveal that during biomass gasification, the carbon-to-oxygen ratio (C / O) is relatively fixed, and hydrogen production is limited by the gasifying agent (air / steam) ratio and the thermodynamic equilibrium of the water-gas shift (WGS) reaction. Under high-temperature conditions, CO2 selectivity increases, resulting in limited hydrogen production. Using water electrolysis to produce hydrogen to supplement H2 leads to excessive energy consumption and poor economic efficiency. Furthermore, biomass gasification syngas typically contains tar. This tar, upon entering the methanol synthesis reactor, condenses and clogs pipes at low temperatures, simultaneously covering active sites on the catalyst surface, leading to catalyst deactivation. The presence of tar also induces side reactions such as CO disproportionation (2CO→C+CO2) or CH4 cracking (CH4→C+2H2), resulting in the formation of a graphitized carbon layer on the methanol synthesis catalyst surface, causing catalyst pore blockage and reduced mechanical strength. Simply relying on thermocatalysis technology cannot effectively address the tar problem; therefore, an additional tar purification unit is required. This not only prolongs the system process but also reduces the carbon conversion rate.

[0026] Based on the above problems, existing technologies have proposed some solutions. For example, patent CN119798037A proposes a method and system for producing green methanol from biomass resources. Its core is to utilize biomass anaerobic fermentation to produce biogas, combined with water electrolysis to produce hydrogen to supplement the hydrogen source. However, this method achieves methanol production through biogas reforming and hydrogen blending, making it highly dependent on green electricity for hydrogen production, leading to increased system energy consumption. Furthermore, the byproduct CO2 still needs to be separated and stored, increasing additional operation and maintenance costs. Patent CN113088337A proposes a device for converting biomass resources into syngas using sliding arc discharge plasma. This solution focuses on the biomass syngas preparation stage, using sliding arc discharge plasma to reduce tar and reformed gas. However, its tar removal effect is still not thorough enough, and it does not combine catalytic reactions for targeted tar conversion; residual tar may still clog downstream equipment.

[0027] Based on the problems existing in related technologies, the inventive concept proposed in this invention is as follows: In the process of reforming biomass syngas crude product, under the action of plasma, the tar in the crude syngas crude product is cracked into CO and H2. Then, with the action of a catalyst, CH4 in the crude syngas crude product undergoes a reforming reaction with water vapor, converting into CO and H2. CO2 in the crude syngas crude product undergoes a dry reforming reaction with CH4, converting into CO and H2. The final mixed gas has an increased H2 content and is almost free of tar, so that the volume ratio of CO to H2 reaches 1:(2.1-2.3), which fully meets the requirements for methanol synthesis.

[0028] To achieve the above-mentioned inventive concept, embodiments of the present invention provide a system for synthesizing methanol from biomass syngas, as described above. Figure 1 The system includes: Reactor 1, plasma generator 2, booster pump 3, and methanol synthesis reactor 4; The reactor 1 includes a first air inlet 11, a second air inlet 12, and an air outlet 13. The first air inlet 11 is used to introduce crude biomass syngas, the second air inlet 12 is used to introduce water vapor, and the air outlet 13 is used to discharge the mixed gas. The reactor 1 is connected to the plasma generator 2; the reactor 1 contains a first catalyst. The booster pump 3 includes an inlet end 31 and an outlet end 32. The inlet end 31 is connected to the outlet 13 through a pipeline, and the outlet end 32 is connected to the inlet of the methanol synthesis reactor 4 through a pipeline. The reactor 1 is configured to cause the tar in the crude syngas to be cracked into CO and H2 under the action of high-density active particles generated by the discharge of the plasma generator 2. Under the action of the first catalyst, the CH4 in the crude syngas undergoes a reforming reaction with the water vapor to be converted into CO and H2. The CO2 in the crude syngas undergoes a dry reforming reaction with the CH4 to be converted into CO and H2. The booster pump 3 is configured to pressurize the mixed gas discharged from the reactor 1 to 2.5 MPa-4 MPa; The methanol synthesis reactor 4 is configured to perform a hydrogenation reaction on the pressurized mixed gas under the action of a second catalyst to synthesize methanol.

[0029] In this embodiment of the invention, the discharge mode of the plasma generator 2 is arc discharge, sliding arc discharge, dielectric barrier discharge, etc. In this embodiment of the invention, the booster pump 3 is a gas compressor or the like; The pressures of the pressurized mixture are 2.5 MPa, 2.7 MPa, 3.0 MPa, 3.2 MPa, 3.4 MPa, 3.6 MPa, 3.8 MPa, and 4 MPa. Pipelines are used to connect various devices in the system. For example, the gas outlet 13 of reactor 1 is connected to the gas inlet 31 of booster pump 3; the gas outlet 32 ​​of booster pump 3 is connected to the inlet of methanol synthesis reactor 4 for conveying gaseous materials.

[0030] In specific implementation, a first catalyst is pre-loaded into reactor 1, and then crude biomass syngas is introduced into reactor 1 through the first inlet 11 and water vapor through the second inlet 12. The plasma generator 2 is activated, causing the tar in the crude syngas to be cracked into CO and H2 under the action of high-density active particles generated by the discharge of the plasma generator 2. At the same time, under the synergistic effect of the first catalyst and the plasma, CH4 in the crude syngas undergoes a reforming reaction with water vapor, converting it into CO and H2. CO2 in the crude syngas undergoes a dry reforming reaction with CH4, converting it into CO and H2. After the above reactions are completed, all CO and H2 in reactor 1 form a mixed gas, which is discharged from reactor 1 through outlet 13. Then, the mixed gas enters the booster pump 3 through inlet 31, is pressurized, and discharged through outlet 32, and finally fed into methanol synthesis reactor 4. A second catalyst is pre-loaded into methanol synthesis reactor 4, and under its catalytic action, a hydrogenation reaction occurs to synthesize methanol.

[0031] The system provided in this invention integrates a plasma generator 2 directly into a reactor 1 loaded with a first catalyst, enabling simultaneous tar cracking, CH4 steam reforming, and CH4 / CO2 dry reforming. This allows for full utilization of the energy carried by the crude syngas, with high-energy plasma particles deeply cracking the tar into CO and H2. Simultaneously, the first catalyst efficiently drives the reforming reaction, replenishing a large amount of H2 and consuming CH4 / CO2. This system fundamentally eliminates the hazards of tar and significantly improves the H2 / CO ratio of the mixed gas, replacing the traditional water-gas shift unit and a separate tar purification unit. The process is extremely simple, and investment and maintenance costs are significantly reduced.

[0032] In an embodiment of the present invention, reference is made to Figure 2 A separator 33 is installed on the pipeline between the air inlet 31 of the booster pump 3 and the air outlet 13 of the reactor 1. The separator 33 is configured to separate solid ash from the mixed gas.

[0033] In this embodiment of the invention, the separator 33 is a cyclone separator, a ceramic filter, etc.; The pipes are made of materials such as 310S stainless steel and corundum ceramic.

[0034] In practice, the mixed gas discharged from the outlet 13 of reactor 1 enters the separator 33 along the pipeline to separate the mixed gas from the solid ash residue, thereby obtaining a pure mixed gas. The separated mixed gas is then introduced into the methanol synthesis reactor 4 along the pipeline for methanol synthesis. By setting up the separator 33, the mixed gas participating in the methanol reaction is made purer, avoiding the introduction of impurities and ensuring high CO conversion rate and methanol selectivity.

[0035] In an embodiment of the present invention, reference is made to Figure 2The separator 33 is provided with a discharge port 34 at the bottom, and a dust collector 35 is connected to the discharge port 34 through a pipe; the dust collector 35 is used to collect the solid ash residue remaining after separation by the separator 33.

[0036] In an embodiment of the present invention, reference is made to Figure 2 The plasma generator 2 is located on one side near the first air inlet 11.

[0037] In this embodiment of the invention, by placing the plasma generator 2 near the first air inlet, the high-density active particles generated by the plasma generator 2 before the crude syngas enters the catalytic zone directly act on the tar molecules, breaking them down in situ into CO and H2, thereby eliminating large molecular hydrocarbons, preventing them from entering subsequent pipelines or contacting the first catalyst, preventing the active sites of the first catalyst from being covered, and ensuring the high activity of the first catalyst.

[0038] In an embodiment of the present invention, reference is made to Figure 2 The system also includes: 5. Feeding device; 6. Fluidized bed gasifier; and 7. Cyclone separator; The feeding device 5 is connected to the inlet of the fluidized bed gasifier 6, the outlet of the fluidized bed gasifier 6 is connected to the inlet of the cyclone separator 7, and the outlet of the cyclone separator 7 is connected to the first air inlet 11 of the reactor 1. The feeding device 5 is configured to transport biomass raw materials to the fluidized bed gasifier 6; The fluidized bed gasifier 6 is configured to promote the gasification reaction between the biomass feedstock and the gasifying agent at a temperature of 700 ℃-1000 ℃ to generate mixed syngas; The cyclone separator 7 is configured to filter the mixed syngas to obtain the crude biomass syngas.

[0039] In this embodiment of the invention, the gas in the fluidized bed gasifier 6 is in a bubbling fluidized state to accelerate the gasification reaction rate; A porous gas distribution plate can be installed at the bottom of the fluidized bed gasifier 6 to ensure uniform gas flow distribution.

[0040] In practice, biomass is introduced into the feeding device 5 and fed into the fluidized bed gasifier 6. At the same time, a gasifying agent is introduced into the fluidized bed gasifier 6. Under the temperature of 700 ℃-1000 ℃ and the action of the gasifying agent, a gasification reaction occurs to obtain mixed syngas. The mixed syngas is then introduced into the cyclone separator 7. After separation, solid particles and other slag are removed to obtain crude biomass syngas.

[0041] In this embodiment of the invention, biomass gasification, purification, tar cracking, reforming (methane steam reforming, methane dry reforming), and methane synthesis are integrated into a continuous system, matching the back-end demand from the front-end raw material processing, thus avoiding the energy consumption loss and compatibility issues of traditional segmented processes.

[0042] In this embodiment of the invention, the fluidized bed gasifier 6 is filled with one of the following: quartz sand, alumina particles, and magnesium oxide particles. These solid particles can enhance heat and mass transfer, thereby achieving efficient gasification.

[0043] In an embodiment of the present invention, reference is made to Figure 2 The cyclone separator 7 includes a slag outlet 71; The slag outlet 71 is connected to the inside of the fluidized bed gasifier 6 via a pipe. The cyclone separator 7 is also configured to return the residue remaining after filtering the mixed syngas to the fluidized bed gasifier 6.

[0044] In practice, the mixed syngas is introduced into the cyclone separator 7 for separation to remove solid particles and other slag, and crude biomass syngas is obtained. The slag is discharged through the slag outlet 71 and then enters the fluidized bed gasifier 6 through the pipeline.

[0045] In this embodiment of the invention, the slag collected by the cyclone separator 7 contains incompletely reacted carbon particles, which are directly fed back to the fluidized bed gasifier 6 for a secondary reaction in the high-temperature gasification environment. This converts the residual carbon into effective syngas components, significantly reducing raw material waste and improving the overall carbon conversion rate of biomass. Furthermore, the high-temperature slag return can supplement the heat of the fluidized bed gasifier 6, buffering temperature changes caused by feed fluctuations and maintaining stable operation of the gasification reaction.

[0046] In an embodiment of the present invention, reference is made to Figure 2 The feeding device 5 includes a hopper 51 and a screw feeder 52; The hopper 51 includes an inlet 511 and an outlet 512, and the screw feeder 52 is connected to the outlet 512 of the hopper 51 and the inlet of the fluidized bed gasifier 6, respectively. The hopper 51 is configured to feed the biomass raw material into and store it through the feed inlet 511, and to discharge the biomass raw material through the discharge outlet 512. The screw feeder 52 is configured to transport the biomass raw material discharged from the hopper 51 to the fluidized bed gasifier 6.

[0047] In practice, biomass raw materials are transported to the silo 51 through the feed inlet 511 and stored in advance. During production, the biomass raw materials are discharged through the discharge outlet 512 and then enter the screw feeder 52. After being fully stirred, they are transported to the fluidized bed gasifier 6 for gasification reaction.

[0048] In this embodiment of the invention, the silo 51 can hold a certain amount of biomass raw materials to offset fluctuations in upstream supply and ensure uninterrupted system operation. The screw feeder 52 achieves precise and uniform conveying of raw materials from the silo 51 to the fluidized bed gasifier 6 through controllable rotation speed, avoiding the risk of blockage or material interruption caused by manual feeding. Furthermore, the continuous and uniform feeding of the screw feeder 52 can maintain a dynamic balance of material concentration, reaction temperature, and gasifying agent ratio within the fluidized bed gasifier 6, suppressing temperature fluctuations caused by uneven feeding.

[0049] In an embodiment of the present invention, reference is made to Figure 2 The hopper 51 includes a first part 513 and a second part 514; The first part 513 is internally connected to the second part 514, and in the target direction, the first part 513 is located above the second part 514; The feed inlet 511 is provided on the side of the first part 513 away from the second part 514, and the discharge outlet 512 is provided on the side of the second part 514 away from the first part 513. The diameter of the second part 514 in the direction perpendicular to the target direction decreases sequentially in the direction toward the first part 513.

[0050] In this embodiment of the invention, the target direction is... Figure 3 The Y direction is shown; like Figure 3 In the Y direction shown, the feed inlet 511 is located at the top of the first part 513, and the discharge outlet 512 is located at the bottom of the second part 514; like Figure 3 The diameter of the second part 514 in the direction perpendicular to the target direction shown in the X direction refers to the diameter of the second part 514 in the X direction. The successively decreasing diameter makes the second part 514 conical.

[0051] In this embodiment of the invention, by setting the diameter of the second part 514 in the direction perpendicular to the target direction to decrease sequentially in the direction toward the first part 513, the biomass raw material will have a centripetal flow tendency along the conical wall of the second part 514 under the action of gravity, thereby destroying the arch support force between the particles, thus avoiding the problem of the biomass raw material being suspended and interrupted in the feeding and the problem of stagnation around the central cavity, and ensuring that the discharge port 512 is continuously unobstructed.

[0052] In practice, the first part 513 can provide sufficient volume to accommodate biomass raw materials and buffer feeding fluctuations; the cross-sectional diameter of the second part 514 shrinks uniformly from top to bottom, guiding the biomass raw materials to flow axially and orderly to the discharge port 512, avoiding deviation or local accumulation, and ensuring that the screw feeder 52 receives a uniform supply.

[0053] In an embodiment of the present invention, reference is made to Figure 2 The system also includes a first heat exchanger 41, a gas-liquid separator 42, and a liquid storage tank 43; The inlet of the first heat exchanger 41 is connected to the outlet of the methanol synthesis reactor 4, the outlet of the first heat exchanger 41 is connected to the inlet of the gas-liquid separator 42, and the outlet of the gas-liquid separator 42 is connected to the inside of the storage tank 43. The first heat exchanger 41 is configured to exchange heat between the methanol discharged from the methanol synthesis reactor 4 and cooling water to obtain cooled methanol. The gas-liquid separator 42 is configured to separate the cooled methanol to obtain liquid methanol and flue gas; The storage tank 43 is configured to store the liquid methanol.

[0054] In specific implementation, the methanol gas synthesized in the methanol synthesis reactor 4 is passed into the first heat exchanger 41, and cooling water is passed into the first heat exchanger 41 to exchange heat between the methanol gas and the cooling water to obtain methanol with a temperature below 60 ℃; the cooled methanol is passed into the gas-liquid separator 42 to separate the cooled methanol from the flue gas with a temperature below 60 ℃ to obtain liquid methanol; the liquid methanol is then transported to the storage tank 43 for storage.

[0055] In this embodiment of the invention, by setting up a first heat exchanger 41, cooling water is used to quickly cool down the high-temperature methanol, so that the gaseous methanol is condensed into liquid. Then, combined with the gas-liquid separator 42, the liquid methanol and non-condensable gas—flue gas—are accurately separated, so as to avoid impurities from entering the product, reduce the subsequent distillation load, and directly produce high-purity methanol.

[0056] In an embodiment of the present invention, reference is made to Figure 2 The system also includes a second heat exchanger 44 and a third heat exchanger 45; The second heat exchanger 44 is connected to the fluidized bed gasifier 6 and the gas outlet of the gas-liquid separator 42, respectively. The third heat exchanger 45 is connected to the reactor 1 and the gas outlet of the gas-liquid separator 42, respectively. The second heat exchanger 44 is configured to supply the gasifying agent to the fluidized bed gasifier 6 and to preheat the gasifying agent using the flue gas discharged from the gas-liquid separator 42; The third heat exchanger 45 is configured to supply steam to the reactor 1 and preheat the steam using the flue gas discharged from the gas-liquid separator 42. The vaporizing agent is air and / or oxygen.

[0057] In this embodiment of the invention, the outlet 13 of the gas-liquid separator 42 is connected to a first pipe 421, and the end of the first pipe 421 away from the gas-liquid separator 42 is connected to a first branch pipe 422 and a second branch pipe 423 respectively. Among them, the end of the first branch pipe 422 away from the first pipe 421 is connected to the inlet of the second heat exchanger 44, and the end of the second branch pipe 423 away from the first pipe 421 is connected to the inlet of the third heat exchanger 45, so as to deliver the flue gas to the second heat exchanger 44 and the third heat exchanger 45 respectively. In this embodiment of the invention, a valve 424 is provided on the first pipe 421 to control the outflow of flue gas. For example, when no gasifying agent is introduced into the second heat exchanger 44, the valve 424 can be closed to prevent flue gas from entering the second heat exchanger 44 and corroding its internal structure. Before the gasifying agent is introduced into the second heat exchanger 44, the valve 424 is opened for a period of time to allow the flue gas to enter the second heat exchanger 44 through the first branch pipe 422 to preheat the second heat exchanger 44. After the gasifying agent is introduced, the gasifying agent is rapidly heated. When no steam is introduced into the third heat exchanger 45, valve 424 can be closed to prevent flue gas from entering the third heat exchanger 45 and corroding its internal structure. Before introducing steam into the third heat exchanger 45, valve 424 can be opened for a period of time to allow flue gas to enter the second heat exchanger 44 through the first branch pipe 422, preheating the second heat exchanger 44. After the gasifying agent is introduced, the gasifying agent can be heated up rapidly. Alternatively, steam and flue gas can be introduced into the third heat exchanger 45 at the same time to heat the steam.

[0058] Valves 424 are also installed on the first branch pipe 422 and the second branch pipe 423 respectively to control the amount of flue gas flowing into the second heat exchanger 44 and the third heat exchanger 45 respectively. For example, when no gasifying agent is introduced into the second heat exchanger 44 or no steam is introduced into the third heat exchanger 45, the valve 424 on the first branch pipe 422 or the second branch pipe 423 can be opened individually to flexibly adjust the emission path of the flue gas.

[0059] The second heat exchanger 44 is configured to supply gasifying agent to the fluidized bed gasifier 6, meaning that when no heat exchange is performed, the gasifying agent can be introduced into the second heat exchanger 44 and directly transported to the fluidized bed gasifier 6 through the second heat exchanger 44. The third heat exchanger 45 is configured to supply steam to reactor 1, meaning that when no heat exchange is being performed, steam can be introduced into the third heat exchanger 45 and directly delivered to reactor 1 via the third heat exchanger 45.

[0060] In practice, the remaining flue gas after separation by the gas-liquid separator 42 is respectively transported to the second heat exchanger 44 and the third heat exchanger 45. A gasifying agent is introduced into the second heat exchanger 44, and steam is introduced into the third heat exchanger 45, allowing the gasifying agent and the flue gas to exchange heat, and the steam to exchange heat with the flue gas. After heat exchange, the gasifying agent is transported to the fluidized bed gasifier 6 for use, and the steam is transported to the reactor 1 for use. The gasifying agent is heated to 400 ℃-500 ℃, and the steam is heated to 600 ℃-700 ℃.

[0061] In this embodiment of the invention, the flue gas discharged from the gas-liquid separator 42 is used to preheat the gasifying agent in the second heat exchanger 44 to reduce the energy consumption of the fluidized bed gasifier 6 in heating the gasifying agent to the reaction temperature; preheating the water vapor in the third heat exchanger 45 can reduce the external energy supply required to meet the steam temperature required for the reforming reaction and reduce the system energy consumption.

[0062] This invention also provides a method for synthesizing methanol from biomass syngas. This method is applicable to the aforementioned system for synthesizing methanol from biomass syngas. (See reference...) Figure 3 The methods include: Step S1: The crude biomass syngas and water vapor are introduced into a reactor equipped with a plasma generator, and the reactor is filled with a first catalyst; In this embodiment of the invention, the temperature of the crude biomass syngas is 700 ℃-1000 ℃.

[0063] It should be noted that this invention does not limit the process and method of converting biomass into crude syngas. Since the conversion of biomass into crude syngas is carried out at high temperatures, the resulting crude syngas itself carries high heat. Therefore, the method for synthesizing methanol from biomass syngas provided by this invention can be combined with any existing known method for converting biomass into crude syngas. This allows direct utilization of the high heat carried by the crude syngas itself to create a high-temperature environment for efficient plasma tar cracking and catalytic reforming reactions, significantly improving tar conversion rate and CH4 / CO2 reforming efficiency. Furthermore, in the syngas produced by traditional biomass gasification, the H2 / CO ratio is 0.8-1.5, and the H2 content is lower than the optimal ratio (2.0-2.2) required for methanol synthesis. In the embodiments of this invention, tar cracking and CH4 / CO2 reforming increase the H2 content, achieving the optimal ratio (2.0-2.2) required for methanol synthesis.

[0064] In this embodiment of the invention, the method for preparing crude syngas includes: Biomass and a gasifying agent are fed into a fluidized bed gasifier. At 700 ℃-1000 ℃, the biomass and the gasifying agent undergo a gasification reaction to obtain crude syngas. The vaporizing agent is air and / or oxygen.

[0065] In this embodiment of the invention, biomass includes straw, sawdust, etc. The gasification reaction temperature is 720 ℃, 760 ℃, 820 ℃, 860 ℃, 920 ℃, 960 ℃ or 980 ℃; The crude biomass syngas mainly includes H2, CO, CO2, CH4, water vapor, and impurities such as tar, carbon black, and hydrogen sulfide; the temperature of the crude biomass syngas is 700 ℃-1000 ℃.

[0066] Step S2: The tar in the crude syngas is decomposed into CO and H2 under the action of high-density active particles generated by the discharge of the plasma generator; In this embodiment of the invention, high-density active particles refer to substances with high chemical activity present in plasma, mainly including high-energy electrons and free radicals; among them, high-energy electrons can directly bombard molecular bonds and initiate pyrolysis; free radicals are -O and -OH, which have unpaired electrons and are extremely chemically active, and can initiate chain reactions to pyrolyze tar.

[0067] In this embodiment of the invention, high-density active particles generated by plasma generator discharge are used to crack tar, which can achieve a tar removal rate of >90% in crude biomass syngas and efficiently remove large molecular hydrocarbon impurities.

[0068] Step S3: Under the action of the first catalyst, CH4 in the crude syngas undergoes a reforming reaction with water vapor, converting into CO and H2; CO2 in the crude syngas undergoes a dry reforming reaction with CH4, converting into CO and H2. In an embodiment of the invention, the first catalyst is pre-loaded inside the reactor to form a first catalyst bed. In this embodiment of the invention, the first catalyst is Fe / Al2O3 and / or Ni / Al2O3.

[0069] Fe / Al2O3 and / or Ni / Al2O3 can efficiently synergize with plasma to strongly drive the methane reforming reaction, maximizing the generation of the required H2 and CO, and effectively improving the H2 / CO ratio. Furthermore, this catalyst exhibits strong resistance to carbon deposition and stability under harsh plasma coupling environments, ensuring long-term stable operation of the system.

[0070] In this embodiment of the invention, the volume ratio of water vapor to crude syngas is (5-10):1.

[0071] In practice, the volume ratio of water vapor to crude syngas is 5:1, 6:1, 7:1, 8:1, 9:1, or 10:1. Excess water vapor can shift the reaction equilibrium towards the product side (CH4 + H2O). The high water vapor concentration significantly improves the CH4 conversion rate, generating more H2 and solving the problem of insufficient H2 / CO ratio. Furthermore, the high water vapor concentration inhibits CH4 cracking (CH4→C+2H2) and CO disproportionation (2CO→C+CO2), protecting the activity of the first catalyst and avoiding the risk of carbon buildup and deactivation.

[0072] Step S4: The mixed gas exported from the reactor is pressurized and then undergoes a hydrogenation reaction under the catalysis of the second catalyst to synthesize methanol.

[0073] In this embodiment of the invention, the volume ratio of CO to H2 in the mixed gas is 1:(2.1-2.3).

[0074] The mixed gas includes CO and H2 from crude biomass syngas, CO and H2 from tar cracking, and CO and H2 obtained from reforming and dry reforming reactions, with almost zero tar content.

[0075] By implementing the above method, the volume ratio of CO to H2 in the mixed gas discharged from the reactor outlet is precisely controlled within the range of 1:(2.1-2.3), which can directly meet the optimal stoichiometric requirements of the methanol synthesis reaction and ensure high methanol selectivity, high yield and high CO conversion rate.

[0076] In this embodiment of the invention, the second catalyst is Pt / CeO2 and / or Cu / ZnO / Al2O3.

[0077] Pt / CeO2 and / or Cu / ZnO / Al2O3 can efficiently catalyze the conversion of mixed gases into methanol, achieving high conversion rate, high selectivity, and high methanol yield. Furthermore, this catalyst exhibits excellent resistance to carbon buildup and stability, ensuring long-term, stable, and efficient operation of the methanol synthesis reactor, thus reducing maintenance costs.

[0078] In this embodiment of the invention, the pressure of the pressurized mixture is 2.5 MPa-4 MPa; The hydrogenation reaction is carried out at a temperature of <200 ℃ and a pressure of <5 MPa.

[0079] In this embodiment of the invention, the mixed gas can synthesize methanol at low temperature, which greatly reduces heat energy consumption (compared to the traditional methane synthesis thermocatalysis which requires high temperature of 200 ℃-300 ℃ and high pressure of 5 MPa-10 MPa, resulting in high energy consumption and strict equipment requirements), significantly improves the overall energy efficiency and economy of the system, and maximizes the high activity and high selectivity of the second catalyst under mild conditions, thereby achieving efficient methanol synthesis.

[0080] In summary, the method provided in this invention utilizes high-density active particles generated by plasma discharge, which possess extremely high energy and can efficiently and directionally decompose tar (complex macromolecular hydrocarbons such as toluene and naphthalene) into CO and H2. This not only eliminates the hazards of tar but also directly transforms tar, which was originally waste, into target gas components, significantly increasing the total amount of H2 and CO in the system. Simultaneously with plasma treatment, the first catalyst packed in the reactor also promotes CH4 vapor reforming and CH4 / CO2 dry reforming reactions, consuming large amounts of CH4 and water vapor and generating CO and a large amount of H2, further optimizing the H2 / CO ratio.

[0081] To enable those skilled in the art to more clearly understand the present invention, a system for synthesizing methanol from biomass syngas according to the present invention will now be described in detail through the following embodiments.

[0082] Example 1 Reference Figure 1 The system shown is for synthesizing methanol from biomass syngas.

[0083] (1) Ni / Al2O3 is pre-filled in reactor 1, and then crude biomass syngas at a temperature of 850 °C is introduced into reactor 1 through the first inlet 11 and water vapor through the second inlet 12, wherein the volume ratio of water vapor to crude biomass syngas is 8:1. (2) Start the plasma generator 2 so that the tar in the crude synthesis gas is decomposed into CO and H2 under the action of the high-density active particles generated by the discharge of the plasma generator 2; (3) At the same time, under the synergistic effect of Ni / Al2O3 and plasma, and under the high temperature environment provided by the crude syngas, CH4 in the crude syngas undergoes a reforming reaction with water vapor, which is converted into CO and H2. (4) At the same time, under the synergistic effect of Ni / Al2O3 and plasma, and in the high temperature environment provided by the crude syngas, CO2 and CH4 in the crude syngas undergo a dry reforming reaction, which converts them into CO and H2. (5) After the reaction in steps (2)-(4) is completed, all CO and H2 in reactor 1 are mixed gas with a volume ratio of 1:(2.1-2.2). The mixed gas is discharged from reactor 1 through outlet 13, and then enters separator 33. After separation, it enters booster pump 3 through inlet 31, is pressurized to 3 MPa, and then discharged through outlet 32. Finally, it is fed into methanol synthesis reactor 4. (6) Cu / ZnO / Al2O3 is pre-filled in methanol synthesis reactor 4. Under its catalytic action and at 180 °C and 3 MPa, a hydrogenation reaction occurs to synthesize methanol.

[0084] Example 2 Reference Figure 2 The system shown is for synthesizing methanol from biomass syngas.

[0085] (1) After the biomass in the silo 51 is discharged through the discharge port 512, it enters the screw feeder 52; the screw feeder 52 transports the biomass to the fluidized bed gasifier 6, and at the same time, air and oxygen are transported to the fluidized bed gasifier 6 through the second heat exchanger 44, so that the fluidized bed gasifier 6 is heated to 850 ℃, which promotes the biomass and gasifying agent to undergo gasification reaction to obtain mixed syngas; (2) The mixed syngas is discharged from the fluidized bed gasifier 6 and then transported to the cyclone separator 7. After separation, crude syngas and slag at a temperature of 850 °C are obtained. The slag is discharged through the slag outlet and sent back to the fluidized bed gasifier 6. The slag provides heat for the gasification reaction. (3) Ni / Al2O3 is pre-filled in reactor 1, and then crude biomass syngas at a temperature of 850 °C is introduced into reactor 1 through the first inlet 11. Water vapor is introduced into reactor 1 through the second inlet 12 via the third heat exchanger 45, wherein the volume ratio of water vapor to crude biomass syngas is 8:1. (4) Start the plasma generator 2 so that the tar in the crude synthesis gas is decomposed into CO and H2 under the action of the high-density active particles generated by the discharge of the plasma generator 2; (5) At the same time, under the synergistic effect of Ni / Al2O3 and plasma, and under the high temperature environment provided by the crude syngas, CH4 in the crude syngas undergoes a reforming reaction with water vapor, which is converted into CO and H2. (6) At the same time, under the synergistic effect of Ni / Al2O3 and plasma, and in the high temperature environment provided by the crude syngas, CO2 and CH4 in the crude syngas undergo a dry reforming reaction, which converts them into CO and H2. (7) After the reaction in steps (4)-(6) is completed, all CO and H2 in reactor 1 are mixed gas with a volume ratio of 1:(2.1-2.2). The mixed gas is discharged from reactor 1 through outlet 13, and then enters separator 33. After separation, it enters booster pump 3 through inlet 31, is pressurized to 3 MPa, and then discharged through outlet 32. Finally, it is fed into methanol synthesis reactor 4. (8) Cu / ZnO / Al2O3 is pre-filled in methanol synthesis reactor 4. Under its catalytic action and at 180 °C and 3 MPa, a hydrogenation reaction occurs to synthesize methanol. (9) Methanol is transported to the first heat exchanger 41, and cooling water is introduced into the first heat exchanger 41 to exchange heat between methanol and cooling water to obtain methanol with a temperature below 60 °C. It is then transported to the gas-liquid separator 42, and after separation, liquid methanol and flue gas with a temperature of 150-200 °C are obtained. The liquid methanol is then transported to the storage tank 43 for storage. (10) The flue gas is delivered to the second heat exchanger 44 and the third heat exchanger 45 respectively. The heat carried by the flue gas is used to preheat the air and oxygen in the second heat exchanger 44 and the water vapor in the third preheater respectively. The preheated air and oxygen enter the fluidized bed gasifier 6 to participate in the subsequent gasification reaction, and the preheated water vapor enters the reactor 1 to participate in the subsequent reaction.

[0086] In summary, this invention provides a system for synthesizing methanol from biomass syngas. A plasma generator is integrated into the reactor. After the crude syngas enters, the high-density active particles generated by the plasma generator decompose the tar in situ into CO and H2, eliminating large molecular hydrocarbons and preventing them from entering subsequent pipelines or contacting the catalyst. Integrating the plasma decomposition zone and the first catalyst bed within the same reactor, coupled with steam injection, not only achieves plasma decomposition of tar to generate additional CO and H2, increasing the total effective gas volume, but also achieves synergistic dual-reaction process, consuming excess CH4 and steam, and simultaneously converting CO2. It also allows for targeted control of the H2 / CO ratio in the mixed gas, ensuring the H2 / CO ratio meets the requirements for methanol synthesis. When synthesizing methanol from biomass syngas, no external hydrogen supplementation is required; the system is self-sufficient, optimizing the gas composition and significantly reducing energy consumption.

[0087] Other configurations of the embodiments of this application, such as ... and ..., and operations, are known to those skilled in the art and will not be described in detail here.

[0088] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. 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.

[0089] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A system for synthesizing methanol from biomass syngas, characterized in that, The system includes: Reactor (1), plasma generator (2), booster pump (3) and methanol synthesis reactor (4); The reactor (1) includes a first air inlet (11), a second air inlet (12) and an air outlet (13). The first air inlet (11) is used to introduce crude biomass syngas, the second air inlet (12) is used to introduce water vapor, and the air outlet (13) is used to discharge the mixed gas. The reactor (1) is connected to the plasma generator (2); the reactor contains a first catalyst. The booster pump (3) includes an inlet end (31) and an outlet end (32). The inlet end (31) is connected to the outlet (13) through a pipeline, and the outlet end (32) is connected to the inlet of the methanol synthesis reactor (4) through a pipeline. The reactor (1) is configured to cause the tar in the crude syngas to crack into CO and H2 under the action of high-density active particles generated by the discharge of the plasma generator, and to promote the CH4 in the crude syngas to undergo a reforming reaction with the water vapor under the action of the first catalyst, converting it into CO and H2; the CO2 in the crude syngas undergoes a dry reforming reaction with the CH4, converting it into CO and H2. The booster pump (3) is configured to pressurize the mixed gas discharged from the reactor (1) to 2.5 MPa-4 MPa; The methanol synthesis reactor (4) is configured to perform a hydrogenation reaction on the pressurized mixed gas under the action of a second catalyst to synthesize methanol.

2. The system for synthesizing methanol from biomass syngas according to claim 1, characterized in that, A separator (33) is installed on the pipeline between the air inlet (31) of the booster pump (3) and the air outlet (13) of the reactor (1); The separator (33) is configured to separate solid ash from the mixed gas.

3. The system for synthesizing methanol from biomass syngas according to claim 1, characterized in that, The plasma generator (2) is located on one side near the first air inlet (11).

4. The system for synthesizing methanol from biomass syngas according to claim 1, characterized in that, The system also includes: Feeding device (5), fluidized bed gasifier (6) and cyclone separator (7); The feeding device (5) is connected to the inlet of the fluidized bed gasifier (6), the outlet of the fluidized bed gasifier (6) is connected to the inlet of the cyclone separator (7), and the outlet of the cyclone separator (7) is connected to the first air inlet (11) of the reactor (1). The feeding device (5) is configured to transport biomass raw materials to the fluidized bed gasifier (6); The fluidized bed gasifier (6) is configured to cause the biomass raw material and the gasifying agent to undergo a gasification reaction at a temperature of 700 ℃-1000 ℃ to generate mixed syngas; The cyclone separator (7) is configured to filter the mixed syngas to obtain the crude biomass syngas.

5. The system for synthesizing methanol from biomass syngas according to claim 4, characterized in that, The fluidized bed gasifier (6) is filled with any one of quartz sand, alumina particles and magnesium oxide particles.

6. The system for synthesizing methanol from biomass syngas according to claim 4, characterized in that, The cyclone separator (7) includes a slag outlet (71); The slag outlet (71) is connected to the inside of the fluidized bed gasifier (6) via a pipe; The cyclone separator (7) is also configured to return the residue remaining after filtering the mixed syngas to the fluidized bed gasifier (6).

7. The system for synthesizing methanol from biomass syngas according to claim 4, characterized in that, The feeding device (5) includes a hopper (51) and a screw feeder (52); The silo (51) includes an inlet (511) and an outlet (512), and the screw feeder (52) is connected to the outlet (512) of the silo (51) and the inlet of the fluidized bed gasifier (6), respectively. The silo (51) is configured to feed and store the biomass raw material through the feed inlet (511) and to discharge the biomass raw material through the discharge outlet (512). The screw feeder (52) is configured to transport the biomass feedstock discharged from the hopper (51) to the fluidized bed gasifier (6).

8. The system for synthesizing methanol from biomass syngas according to claim 7, characterized in that, The hopper (51) includes a first part (513) and a second part (514); The first part (513) is internally connected to the second part (514), and in the target direction, the first part (513) is located above the second part (514); The feed inlet (511) is provided on the side of the first part (513) away from the second part (514), and the discharge outlet (512) is provided on the side of the second part (514) away from the first part (513). The diameter of the second part (514) in the direction perpendicular to the target decreases sequentially in the direction toward the first part (513).

9. The system for synthesizing methanol from biomass syngas according to claim 4, characterized in that, The system also includes a first heat exchanger (41), a gas-liquid separator (42), and a liquid storage tank (43); The inlet of the first heat exchanger (41) is connected to the outlet of the methanol synthesis reactor (4), the outlet of the first heat exchanger (41) is connected to the inlet of the gas-liquid separator (42), and the outlet of the gas-liquid separator (42) is connected to the inside of the storage tank (43). The first heat exchanger (41) is configured to exchange heat between the methanol discharged from the methanol synthesis reactor (4) and cooling water to obtain cooled methanol; The gas-liquid separator (42) is configured to separate the cooled methanol to obtain liquid methanol and flue gas; The storage tank (43) is configured to store the liquid methanol.

10. The system for synthesizing methanol from biomass syngas according to claim 9, characterized in that, The system also includes a second heat exchanger (44) and a third heat exchanger (45); The second heat exchanger (44) is connected to the fluidized bed gasifier (6) and the gas outlet of the gas-liquid separator (42), respectively; The third heat exchanger (45) is connected to the reactor (1) and the gas outlet of the gas-liquid separator (42), respectively. The second heat exchanger (44) is configured to supply the gasifying agent to the fluidized bed gasifier (6) and to preheat the gasifying agent using the flue gas discharged from the gas-liquid separator (42); The third heat exchanger (45) is configured to supply steam to the reactor (1) and preheat the steam using the flue gas discharged from the gas-liquid separator (42); The vaporizing agent is air and / or oxygen.

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