System for preparing green methanol synthesis gas by coupling biomass fluidized bed gasification with green hydrogen

Abstract

The invention belongs to the technical field of biomass gasification, and particularly relates to a system for preparing green methanol synthesis gas by coupling biomass fluidized bed gasification with green hydrogen, which comprises a biomass gasification unit, the biomass gasification unit is connected with a waste heat recovery and dust removal washing purification unit, the waste heat recovery and dust removal washing purification unit is connected with a partial oxidation unit, and the partial oxidation unit is connected with a secondary oxidation unit. The partial oxidation unit is connected with the decarburization unit, the decarburization unit is connected with the gas mixing storage tank, carbon dioxide separated by the decarburization unit flows back to the biomass gasification unit, and a hydrogen inlet of the gas mixing storage tank is connected with a hydrogen outlet of the electrolyzed water unit through a pipeline. A hydrogen outlet of the electrolyzed water unit is respectively connected with hydrogen inlets of the biomass gasification unit and the partial oxidation unit through pipelines, energy flow in the process is optimized through reasonable allocation of hydrogen, the problem of unreasonable energy and substance circulation in the prior art is solved, and the energy utilization rate of the biomass gasification unit is improved. The yield and the economical efficiency of the green methanol synthesis gas are obviously improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of biomass gasification, and in particular relates to a system for producing green methanol synthesis gas by coupling biomass fluidized bed gasification with green hydrogen. Background Art

[0002] Green methanol is a type of methanol produced from renewable resources. Its production process is characterized by low carbon and environmental protection, which is in line with the global energy transformation and carbon neutrality goals. Unlike traditional methanol production methods, the preparation of green methanol usually relies on clean energy such as biomass, green hydrogen, or carbon dioxide capture and utilization. In addition, methanol, as an important chemical raw material, can be used to synthesize fuels, chemicals, and as an energy carrier. It has important economic value and environmental significance. At present, the preparation of green methanol faces problems such as low yield, high cost, and low energy efficiency. Therefore, improving the yield of green methanol synthesis gas, optimizing energy efficiency, and reducing production costs are key directions for future technological development.

[0003] Biomass gasification is the process of converting solid biomass into combustible gas through heating and gasification reaction. Fluidized bed gasification technology is one of the mature methods of biomass gasification. It uses a fluidized bed gasifier to effectively maintain full contact between biomass particles and gasification agents and promote the gasification reaction. Compared with fixed bed gasification and fluidized bed gasification, it has stronger raw material adaptability, simple raw material and coal gas processing characteristics and higher economy, and is suitable for large-scale industrial biomass gasification. Although fluidized bed gasification technology has great advantages, there are still some technical bottlenecks and challenges in the preparation of green methanol synthesis gas.

[0004] Patent CN 118064185 A discloses a system for preparing green methanol by gasifying biomass. The system is provided with a biomass gasification unit, a compression unit and a methanol synthesis unit connected in sequence. The biomass enters the gasification unit through a feeding device, and is fully gasified in the gasification unit to obtain synthesis gas. The synthesis gas passes through a cracking device, a waste heat recovery device and a dust removal device in sequence, and then passes through a compression unit and a methanol synthesis unit to produce green methanol. The whole system has the advantages of good environmental protection indicators, high system energy efficiency, high continuous operation rate of the device, large load adjustment range, convenient start and stop, high degree of automation, safety and reliability. However, it does not effectively separate and utilize carbon dioxide from the synthesis gas. Carbon dioxide has high energy consumption as a raw gas for methanol synthesis, and the reaction rate is slow. In comparison, carbon monoxide is a more mature and efficient raw gas for methanol synthesis.

[0005] Patent CN 116814300 A discloses a highly efficient biomass gasification system for producing green methanol, which includes: a solar and wind power generation water electrolysis subsystem, a biomass gasification subsystem, a syngas conversion subsystem, and a methanol synthesis subsystem. The oxygen generated by the solar and wind power generation water electrolysis subsystem is used as a gasification medium of the biomass gasification subsystem to synthesize a biomass syngas with a higher calorific value. The biomass syngas passes through the syngas conversion subsystem and is sent to the methanol synthesis subsystem to synthesize methanol. This invention is a green, environmentally friendly and energy-saving system. The energy consumed is all renewable energy. The system's products "green hydrogen" and "green methanol" are all green products. There is less pollution and low energy consumption in the production process, which fully reflects the concept of sustainable development and emission reduction. However, the carbon dioxide in the gasification process is not effectively recycled. A large amount of carbon dioxide participates in methanol synthesis, which will generate more energy consumption, which leads to a waste of resources and increases the carbon dioxide emissions of the system. In addition, the supply and demand of hydrogen are not balanced, and the production of hydrogen does not match the amount of hydrogen required for gasification reaction and green methanol synthesis, resulting in additional energy consumption. Summary of the invention

[0006] In order to solve the above-mentioned problems of unbalanced use of hydrogen and improper treatment of carbon dioxide leading to low production efficiency, the present invention provides a system for producing green methanol synthesis gas by coupling green hydrogen with biomass fluidized bed gasification.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] A system for producing green methanol synthesis gas by coupling biomass fluidized bed gasification with green hydrogen comprises a biomass gasification unit, wherein the biomass gasification unit adopts a pressurized fluidized bed gasification technology to suspend biomass raw materials and fully contact them with a gasifying agent for gasification to prepare synthetic raw gas, wherein the raw gas outlet of the biomass gasification unit is connected to the raw gas inlet of a waste heat recovery and dust removal and water washing purification unit through a pipeline, wherein the waste heat recovery and dust removal and water washing purification unit recovers and purifies the raw gas, wherein the raw gas outlet of the waste heat recovery and dust removal and water washing purification unit is connected to the raw gas inlet of a partial oxidation unit through a pipeline, wherein the partial oxidation unit performs a partial oxidation reaction on the raw gas to generate low-methane synthesis gas, wherein the low-methane synthesis gas outlet of the partial oxidation unit is connected to the low-methane synthesis gas outlet of a decarbonization unit through a pipeline. The methane synthesis gas inlet, the gas outlet of the decarbonization unit is connected to the gas mixing tank through a pipeline, the carbon dioxide separated by the decarbonization unit flows back to the biomass gasification unit, the hydrogen inlet of the gas mixing tank is connected to the hydrogen outlet of the water electrolysis unit through a pipeline, the hydrogen and the purified synthesis gas produced by the decarbonization unit are blended to form green methanol synthesis gas, the hydrogen outlet of the water electrolysis unit is also connected to the hydrogen inlets of the biomass gasification unit and the partial oxidation unit through pipelines, the oxygen outlet of the water electrolysis unit is connected to the oxygen inlets of the biomass gasification unit and the partial oxidation unit through pipelines, the steam outlet of the waste heat recovery and dust removal water washing purification unit and the steam outlet of the partial oxidation unit are both connected to the water vapor inlet of the biomass gasification unit through pipelines.

[0009] Furthermore, the water electrolysis unit includes an electrolytic cell, which is provided with a hydrogen outlet and an oxygen outlet. The hydrogen outlet of the electrolytic cell is respectively connected to the hydrogen inlets of the biomass gasification unit, the partial oxidation unit and the gas mixing tank through pipelines, and the oxygen outlet of the electrolytic cell is respectively connected to the oxygen inlets of the biomass gasification unit and the partial oxidation unit through pipelines.

[0010] Furthermore, the biomass gasification unit includes a fluidized bed gasifier, a hydrogen inlet at the upper end of the fluidized bed gasifier is connected to the hydrogen inlet of the electrolytic cell through a pipeline, a raw gas outlet of the fluidized bed gasifier is connected to the raw gas inlet of the waste heat recovery and dust removal and water washing purification unit through a pipeline, an oxygen inlet of the fluidized bed gasifier is connected to the oxygen outlet of the electrolytic cell through a pipeline, a steam inlet of the fluidized bed gasifier is connected to the steam outlets of the waste heat recovery and dust removal and water washing purification unit and the partial oxidation unit through pipelines, and a carbon dioxide inlet of the fluidized bed gasifier is connected to the carbon dioxide outlet of the decarbonization unit through a pipeline.

[0011] Furthermore, the waste heat recovery and dust removal water washing purification unit includes a No. 1 waste heat recovery device, the air inlet of the No. 1 waste heat recovery device is connected to the raw gas outlet of the fluidized bed gasifier through a pipeline, the steam outlet of the No. 1 waste heat recovery device is connected to the steam inlet of the fluidized bed gasifier through a pipeline, the air outlet of the No. 1 waste heat recovery device is connected to the air inlet of the cyclone separator through a pipeline, the air outlet of the cyclone separator is connected to the air inlet of the No. 1 water washing tower through a pipeline, and the raw gas outlet of the No. 1 water washing tower is connected to the raw gas inlet of the partial oxidation unit through a pipeline.

[0012] Furthermore, the partial oxidation unit includes a gas integration box, the oxygen inlet of the gas integration box is connected to the oxygen outlet of the electrolytic cell through a pipeline, the raw gas inlet of the gas integration box is connected to the raw gas outlet of the No. 1 water scrubber through a pipeline, the raw gas outlet of the gas integration box is connected to the inlet of the POX furnace through a pipeline, a hydrogen inlet is provided in the middle of the POX furnace, the hydrogen inlet of the POX furnace is connected to the hydrogen outlet of the electrolytic cell through a pipeline, the outlet of the POX furnace is connected to the inlet of the No. 2 waste heat recovery device through a pipeline, the steam outlet of the No. 2 waste heat recovery device is connected to the steam inlet of the fluidized bed gasification furnace through a pipeline, the raw gas outlet of the No. 2 waste heat recovery device is connected to the inlet of the No. 2 water scrubber through a pipeline, and the outlet of the No. 2 water scrubber is connected to the synthesis gas inlet of the decarbonization unit through a pipeline.

[0013] Furthermore, the decarbonization unit includes a decarbonization device, the synthesis gas inlet of the decarbonization device is connected to the outlet of the No. 2 water washing tower through a pipeline, the carbon dioxide outlet of the decarbonization device is connected to the carbon dioxide inlet of the fluidized bed gasification furnace through a pipeline, and the outlet of the decarbonization device is connected to the gas mixing tank through a pipeline.

[0014] Furthermore, the decarbonization unit is any one of a physical adsorption decarbonization device, a chemical absorption decarbonization device or a membrane separation decarbonization device.

[0015] Furthermore, the water electrolysis unit is powered by renewable energy to ensure the green and low-carbon characteristics of the system.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] 1. The present invention divides hydrogen into three parts. The first part is transported to the biomass gasification unit and sprayed into the top of the fluidized bed gasifier to participate in the reverse water gas shift reaction, which not only effectively reduces the temperature at the top of the gasifier, but also partially converts carbon dioxide into carbon monoxide, optimizes the ratio of gas components, and makes it more suitable for the needs of methanol synthesis reaction; the second part is transported to the partial oxidation unit and sprayed from the middle of the POX furnace to quench the high-temperature coal gas and reduce the by-products generated in the partial oxidation reaction of methane: carbon dioxide, aldehydes and ketones, and convert them into more valuable products: carbon monoxide and alcohols; the third part is transported to the gas mixing tank to further regulate the ratio of hydrogen to carbon monoxide to ensure that the generated synthesis gas meets the optimal process requirements for green methanol synthesis. Through the reasonable allocation of hydrogen, the energy flow in the process is optimized, the problem of unreasonable energy and material circulation in the existing process is solved, and the yield and economy of green methanol synthesis gas are significantly improved.

[0018] 2. The present invention recycles and reuses carbon dioxide, and the carbon dioxide separated from the decarbonization device is returned to the fluidized bed gasifier as circulating gas, replacing the water vapor and nitrogen commonly used in the traditional fluidized bed process as a gasifying agent or pressurized blowing gas. This design not only reduces energy consumption, improves the utilization rate of carbon dioxide, and greatly reduces the wastewater generated by steam condensation, thereby improving the overall thermal energy utilization efficiency of the system and reducing environmental pollution.

[0019] 3. The present invention adopts renewable energy to power the water electrolysis unit, and fully realizes a green and low-carbon energy supply mode; the reasonable regulation of gas ratio and the efficient collaboration of multi-unit coupling construct a green methanol synthesis gas production system with low energy consumption and high resource utilization; compared with the traditional methanol synthesis process, the system greatly reduces the dependence on fossil fuels, reduces the emission of waste gas and wastewater, and constructs a multi-synergistic, green and low-carbon methanol synthesis gas preparation system, which is in line with the trend of green development in the modern chemical industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the present invention;

[0021] Figure 2 is a system flow chart of the present invention;

[0022] In the figure, there are an electrolytic cell 1, a fluidized bed gasifier 2, a No. 1 waste heat recovery device 3, a cyclone separator 4, a No. 1 water scrubber 5, a gas integration box 6, a POX furnace 7, a No. 2 waste heat recovery device 8, a No. 2 water scrubber 9, a decarbonization device 10, and a gas mixing tank 11. DETAILED DESCRIPTION

[0023] In order to further illustrate the technical solution of the present invention, the present invention is further described below through embodiments.

[0024] like Figure 1 and Figure 2As shown, a system for producing green methanol synthesis gas by coupling biomass fluidized bed gasification with green hydrogen includes a biomass gasification unit. The biomass gasification unit uses a pressurized fluidized bed gasification technology to suspend biomass raw materials and fully contact them with a gasifying agent for gasification to prepare synthetic raw gas. The raw gas outlet of the biomass gasification unit is connected to the raw gas inlet of a waste heat recovery and dust removal and water washing purification unit through a pipeline. The biomass gasification unit includes a fluidized bed gasifier 2. The hydrogen inlet at the upper end of the fluidized bed gasifier 2 is connected to the hydrogen inlet of an electrolytic cell 1 through a pipeline. The raw gas outlet of the fluidized bed gasifier 2 is connected to the raw gas inlet of the waste heat recovery and dust removal and water washing purification unit through a pipeline. The oxygen inlet of the fluidized bed gasifier 2 is connected to the raw gas inlet of the waste heat recovery and dust removal and water washing purification unit through a pipeline. The oxygen outlet of the electrolytic cell 1 is connected to the oxygen outlet of the electrolytic cell 1 through a pipeline, the steam inlet of the fluidized bed gasifier 2 is connected to the steam outlets of the waste heat recovery and dust removal water washing purification unit and the partial oxidation unit through pipelines, the carbon dioxide inlet of the fluidized bed gasifier 2 is connected to the carbon dioxide outlet of the decarbonization unit through a pipeline, the waste heat recovery and dust removal water washing purification unit recovers and purifies the raw gas, the waste heat recovery and dust removal water washing purification unit includes a No. 1 waste heat recovery device 3, the air inlet of the No. 1 waste heat recovery device 3 is connected to the raw gas outlet of the fluidized bed gasifier 2 through a pipeline, the steam outlet of the No. 1 waste heat recovery device 3 is connected to the steam inlet of the fluidized bed gasifier 2 through a pipeline, and the outlet of the No. 1 waste heat recovery device 3 is connected to the steam outlet of the fluidized bed gasifier 2 through a pipeline. The pipeline is connected to the air inlet of the cyclone separator 4, the air outlet of the cyclone separator 4 is connected to the air inlet of the No. 1 water washing tower 5 through a pipeline, the raw gas outlet of the No. 1 water washing tower 5 is connected to the raw gas inlet of the partial oxidation unit through a pipeline, the raw gas outlet of the waste heat recovery and dust removal water washing purification unit is connected to the raw gas inlet of the partial oxidation unit through a pipeline, the partial oxidation unit includes a gas integration box 6, the hydrogen inlet of the gas integration box 6 is connected to the hydrogen outlet of the electrolytic cell 1 through a pipeline, the oxygen inlet of the gas integration box 6 is connected to the oxygen outlet of the electrolytic cell 1 through a pipeline, the raw gas inlet of the gas integration box 6 is connected to the raw gas outlet of the No. 1 water washing tower 5 through a pipeline, the raw gas outlet of the gas integration box 6 The feed gas outlet is connected to the air inlet of the POX furnace 7 through a pipeline, the air outlet of the POX furnace 7 is connected to the air inlet of the No. 2 waste heat recovery device 8 through a pipeline, the steam outlet of the No. 2 waste heat recovery device 8 is connected to the steam inlet of the fluidized bed gasifier 2 through a pipeline, the feed gas outlet of the No. 2 waste heat recovery device 8 is connected to the air inlet of the No. 2 water scrubber 9 through a pipeline, the air outlet of the No. 2 water scrubber 9 is connected to the synthesis gas inlet of the decarbonization unit through a pipeline, the partial oxidation unit performs a partial oxidation reaction on the feed gas to generate a low-methane synthesis gas, the low-methane synthesis gas outlet of the partial oxidation unit is connected to the low-methane synthesis gas inlet of the decarbonization unit through a pipeline, and the air outlet of the decarbonization unit is connected to the gas mixing tank 11 through a pipeline.The carbon dioxide separated by the decarbonization unit flows back to the biomass gasification unit, the hydrogen inlet of the gas mixing tank 11 is connected to the hydrogen outlet of the water electrolysis unit through a pipeline, the hydrogen is mixed with the purified synthesis gas produced by the decarbonization unit to form green methanol synthesis gas, the hydrogen outlet of the water electrolysis unit is also connected to the hydrogen inlet of the biomass gasification unit and the partial oxidation unit through a pipeline, the oxygen outlet of the water electrolysis unit is connected to the oxygen inlet of the biomass gasification unit and the partial oxidation unit through a pipeline, the steam of the waste heat recovery and dust removal water washing purification unit The gas outlet and the steam outlet of the partial oxidation unit are connected to the steam inlet of the biomass gasification unit through a pipeline. The water electrolysis unit includes an electrolytic cell 1, which is provided with a hydrogen outlet and an oxygen outlet. The hydrogen outlet of the electrolytic cell 1 is connected to the hydrogen inlets of the biomass gasification unit, the partial oxidation unit and the gas mixing tank through pipelines, and the oxygen outlet of the electrolytic cell 1 is connected to the oxygen inlets of the biomass gasification unit and the partial oxidation unit through pipelines. The water electrolysis unit is powered by renewable energy to ensure the green and low-carbon characteristics of the system.

[0025] The decarbonization unit includes a decarbonization device 10, the synthesis gas inlet of the decarbonization device 10 is connected to the outlet of the No. 2 water scrubber 9 through a pipeline, the carbon dioxide outlet of the decarbonization device 10 is connected to the carbon dioxide inlet of the fluidized bed gasifier 2 through a pipeline, and the outlet of the decarbonization device 10 is connected to the gas mixing tank 11 through a pipeline. The decarbonization unit is any one of a physical adsorption decarbonization device, a chemical absorption decarbonization device or a membrane separation decarbonization device.

[0026] Example 1: Hydrogen ratio optimization is used for coupling the biomass gasification unit with the decarbonization unit. In this example, the hydrogen produced by the water electrolysis unit is divided into three parts:

[0027] The first hydrogen (30%) is directly introduced into the top of the biomass gasification unit to promote the reverse water-gas shift reaction, convert part of the carbon dioxide into carbon monoxide, and effectively reduce the top temperature of the gasifier to optimize the gasification conditions.

[0028] The second hydrogen (50%) is sent to the partial oxidation unit and sprayed into the bottom of the high-temperature thermal reforming reactor to participate in the reverse water-gas shift reaction, further converting carbon dioxide into carbon monoxide, while quenching the high-temperature gas to maintain a stable reaction temperature.

[0029] The third hydrogen (20%) is mixed with the raw gas purified by the decarbonization unit to adjust the final hydrogen to carbon monoxide ratio to 2.05:1 to ensure the optimal process requirements for green methanol synthesis gas.

[0030] Example 2: Adjustment of hydrogen ratio to adapt to the treatment of raw gas with high carbon dioxide concentration. When the raw gas has a high carbon dioxide concentration, the distribution ratio of hydrogen is adjusted as follows:

[0031] The first hydrogen (40%): increase the injection amount to the top of the biomass gasification unit, increase the production of carbon monoxide by strengthening the reverse water-gas shift reaction, and optimize the temperature distribution of the gasifier.

[0032] The second hydrogen (40%) is sent to the partial oxidation unit to adjust the temperature of the thermal reforming reaction and convert excess carbon dioxide into carbon monoxide to reduce the methane content.

[0033] The third hydrogen (20%): maintains the mixing ratio with the purified gas from the decarbonization unit, and the ratio of hydrogen to carbon monoxide in the final synthesis gas is controlled at 2.1:1 to meet the conversion requirements of high carbon dioxide content gas.

[0034] Example 3: Hydrogen ratio optimization to adapt to low carbon dioxide concentration feed gas. Under the condition of low carbon dioxide concentration in the feed gas, the hydrogen distribution ratio is as follows:

[0035] The first hydrogen (20%): appropriately reduce the amount of hydrogen injected into the biomass gasification unit to avoid excessive reverse water-gas shift reaction leading to excessive carbon monoxide production, thereby avoiding unnecessary increase in energy consumption.

[0036] The second hydrogen path (50%) is distributed in large proportion to the partial oxidation unit to promote the generation of low-methane synthesis gas and optimize the conversion efficiency of carbon dioxide in the raw gas.

[0037] The third hydrogen (30%): Increase the mixing ratio with the purified gas from the decarbonization unit to ensure that the ratio of hydrogen to carbon monoxide reaches 1.8:1, which is suitable for methanol synthesis conditions under low carbon dioxide concentration.

[0038] The above shows and describes the main features and advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes that fall within the meaning and scope of the equivalent elements of the claims are included in the present invention.

[0039] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A system for producing green methanol synthesis gas by coupling biomass fluidized bed gasification with green hydrogen, characterized in that: It includes a biomass gasification unit, which adopts a pressurized fluidized bed gasification technology to suspend biomass raw materials and fully contact them with a gasifying agent for gasification to prepare synthetic raw gas, the raw gas outlet of the biomass gasification unit is connected to the raw gas inlet of a waste heat recovery and dust removal and water washing purification unit through a pipeline, the waste heat recovery and dust removal and water washing purification unit recovers and purifies the raw gas, the raw gas outlet of the waste heat recovery and dust removal and water washing purification unit is connected to the raw gas inlet of a partial oxidation unit through a pipeline, the partial oxidation unit performs a partial oxidation reaction on the raw gas to generate low-methane synthesis gas, the low-methane synthesis gas outlet of the partial oxidation unit is connected to the low-methane synthesis gas inlet of a decarbonization unit through a pipeline, and the decarbonization unit The gas outlet is connected to the gas mixing tank (11) through a pipeline, and the carbon dioxide separated by the decarbonization unit flows back to the biomass gasification unit. The hydrogen inlet of the gas mixing tank (11) is connected to the hydrogen outlet of the water electrolysis unit through a pipeline. The hydrogen is mixed with the purified synthesis gas generated by the decarbonization unit to form green methanol synthesis gas. The hydrogen outlet of the water electrolysis unit is also connected to the hydrogen inlets of the biomass gasification unit and the partial oxidation unit through pipelines. The oxygen outlet of the water electrolysis unit is connected to the oxygen inlets of the biomass gasification unit and the partial oxidation unit through pipelines. The steam outlet of the waste heat recovery and dust removal water washing purification unit and the steam outlet of the partial oxidation unit are both connected to the steam inlet of the biomass gasification unit through pipelines.

2. According to claim 1, a system for producing green methanol synthesis gas by coupling biomass fluidized bed gasification with green hydrogen is characterized by: The water electrolysis unit comprises an electrolytic cell (1), wherein the electrolytic cell (1) is provided with a hydrogen outlet and an oxygen outlet, wherein the hydrogen outlet of the electrolytic cell (1) is respectively connected to the hydrogen inlets of a biomass gasification unit, a partial oxidation unit and a gas mixing tank through pipelines, and the oxygen outlet of the electrolytic cell (1) is respectively connected to the oxygen inlets of the biomass gasification unit and the partial oxidation unit through pipelines.

3. The system for producing green methanol synthesis gas by coupling biomass fluidized bed gasification with green hydrogen according to claim 1 is characterized by: The biomass gasification unit comprises a fluidized bed gasifier (2), wherein a hydrogen inlet at the upper end of the fluidized bed gasifier (2) is connected to a hydrogen inlet of an electrolytic cell (1) via a pipeline, a raw gas outlet of the fluidized bed gasifier (2) is connected to a raw gas inlet of a waste heat recovery and dust removal and water washing purification unit via a pipeline, an oxygen inlet of the fluidized bed gasifier (2) is connected to an oxygen outlet of the electrolytic cell (1) via a pipeline, a steam inlet of the fluidized bed gasifier (2) is connected to steam outlets of the waste heat recovery and dust removal and water washing purification unit and a partial oxidation unit via pipelines, and a carbon dioxide inlet of the fluidized bed gasifier (2) is connected to a carbon dioxide outlet of a decarbonization unit via a pipeline.

4. The system for producing green methanol synthesis gas by coupling biomass fluidized bed gasification with green hydrogen according to claim 1 is characterized by: The waste heat recovery and dust removal water washing purification unit comprises a No. 1 waste heat recovery device (3), the air inlet of the No. 1 waste heat recovery device (3) is connected to the raw gas outlet of the fluidized bed gasifier (2) through a pipeline, the steam outlet of the No. 1 waste heat recovery device (3) is connected to the steam inlet of the fluidized bed gasifier (2) through a pipeline, the air outlet of the No. 1 waste heat recovery device (3) is connected to the air inlet of the cyclone separator (4) through a pipeline, the air outlet of the cyclone separator (4) is connected to the air inlet of the No. 1 water washing tower (5) through a pipeline, and the raw gas outlet of the No. 1 water washing tower (5) is connected to the raw gas inlet of the partial oxidation unit through a pipeline.

5. The system for producing green methanol synthesis gas by coupling biomass fluidized bed gasification with green hydrogen according to claim 1 is characterized by: The partial oxidation unit comprises a gas integration box (6), the oxygen inlet of the gas integration box (6) is connected to the oxygen outlet of the electrolytic cell (1) through a pipeline, the raw gas inlet of the gas integration box (6) is connected to the raw gas outlet of the first water scrubber (5) through a pipeline, the raw gas outlet of the gas integration box (6) is connected to the air inlet of the POX furnace (7) through a pipeline, the POX furnace (7) is provided with a hydrogen inlet, and the POX furnace (7) is provided with a hydrogen inlet passage The hydrogen outlet of the electrolytic cell (1) is connected through a pipeline, the outlet of the POX furnace (7) is connected to the air inlet of the No. 2 waste heat recovery device (8) through a pipeline, the steam outlet of the No. 2 waste heat recovery device (8) is connected to the steam inlet of the fluidized bed gasification furnace (2) through a pipeline, the raw gas outlet of the No. 2 waste heat recovery device (8) is connected to the air inlet of the No. 2 water scrubber (9) through a pipeline, and the outlet of the No. 2 water scrubber (9) is connected to the synthesis gas inlet of the decarbonization unit through a pipeline.

6. The system for producing green methanol synthesis gas by coupling biomass fluidized bed gasification with green hydrogen according to claim 1 is characterized by: The decarbonization unit comprises a decarbonization device (10), the synthesis gas inlet of the decarbonization device (10) is connected to the outlet of the second water scrubber (9) via a pipeline, the carbon dioxide outlet of the decarbonization device (10) is connected to the carbon dioxide inlet of the fluidized bed gasifier (2) via a pipeline, and the outlet of the decarbonization device (10) is connected to the gas mixing tank (11) via a pipeline.

7. The system for producing green methanol synthesis gas by coupling biomass fluidized bed gasification with green hydrogen according to claim 6 is characterized by: The decarbonization unit is any one of a physical adsorption decarbonization device (10), a chemical absorption decarbonization device (10) or a membrane separation decarbonization device (10).

8. The system for producing green methanol synthesis gas by coupling biomass fluidized bed gasification with green hydrogen according to claim 2 is characterized by: The water electrolysis unit is powered by renewable energy to ensure the green and low-carbon characteristics of the system.

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