System and method for producing methanol from biomass raw material

Abstract

The invention discloses a system and a method for producing methanol from a biomass raw material. The system comprises a purification device, a dry reforming reaction device and a methanol synthesis reaction device, the purification device is connected to the dry reforming reaction device and is used for carrying out dry reforming reaction on the purified biomass synthesis gas serving as part of or all raw material gas; the dry reforming reaction device is connected to the methanol synthesis reaction device; a hydrogen supplementing opening is formed in a pipeline for connecting the dry reforming reaction device and the methanol synthesis reaction device and is used for supplementing hydrogen into the reformed gas to obtain mixed gas; a product flowing out of the methanol synthesis reaction device contains methanol. According to the invention, dry reforming is carried out on the biomass synthesis gas, and methanol synthesis is directly carried out after the hydrogen-carbon ratio of the reformed gas is adjusted in a hydrogen supplementing manner, so that the production process of methanol is simplified, efficient conversion of green carbon in the biomass synthesis gas is realized, and no extra carbon dioxide emission is generated.

Description

Technical Field

[0001] The present invention relates to a system and method for producing methanol from biomass raw materials, belonging to the technical field of methanol production. Background Art

[0002] Bioenergy is an important renewable energy source, featuring characteristics such as green, low-carbon, clean, and renewable. Using syngas obtained from biomass gasification as raw materials to prepare chemicals such as methanol and olefins can not only achieve the high-value conversion of biomass but also increase the green attributes of products, ultimately realizing the green and low-carbon transformation of the entire industrial chain.

[0003] The biogas obtained from the anaerobic fermentation of biomass is generally used to separate methane for sale as biomethane or for biomass gas power generation. These utilization methods inevitably emit gases such as methane or a large amount of carbon dioxide. Converting biogas into methanol, which is convenient for storage and transportation, is a possible idea for the efficient utilization of biomass energy. Methanol is the basic central product of C1 chemistry. Among the basic organic chemical raw materials, methanol consumption ranks only after ethylene, propylene, and benzene, and it is an important bulk chemical product. The downstream applications of methanol are very extensive. In recent years, as an environmentally friendly energy source, fuel, and hydrogen energy storage and transportation carrier, it has also received favor at home and abroad. In contemporary society, methanol is a chemical product with high added value and has great development potential. It is very necessary to convert as much green carbon in biogas into green methanol while minimizing carbon dioxide emissions during the production process.

[0004] CN116789520A provides a method for producing methanol from skid-mounted self-sufficient biogas, but the energy source for its reforming reaction mainly comes from burning a part of the biogas in the combustion chamber of the combustion furnace, which not only wastes the green carbon source but also causes unnecessary additional carbon dioxide emissions.

[0005] CN111547678A provides a method for thermally catalytically producing methanol from the whole components of biogas, but its reforming reaction requires the mixing of biogas and water vapor for dry and wet dual reforming, which will inevitably reduce the carbon conversion rate in biogas. At the same time, the heat exchange and separation system of this technology is relatively complex, increasing the overall production cost.

[0006] In view of the shortcomings of the existing methanol production technology from biomass raw materials, it is necessary to develop a new process for producing methanol from biomass raw materials to simplify the methanol production process, efficiently convert the green carbon in biomass raw materials, and at the same time not produce additional carbon dioxide emissions. Summary of the Invention

[0007] To solve the above technical problems, the object of the present invention is to provide a system and method for producing methanol from biomass raw materials. The present invention uses biomass syngas for dry reforming, and after adjusting the hydrogen-carbon ratio of the reformed gas obtained by dry reforming by means of hydrogen supplementation, directly conducts methanol synthesis, which can simplify the methanol production process, realize the efficient conversion of green carbon in biomass syngas, and at the same time does not generate additional carbon dioxide emissions.

[0008] To achieve the above object, in the first aspect of the present invention, a system for producing methanol from biomass raw materials is provided, which includes: a purification device, a dry reforming reaction device, and a methanol synthesis reaction device;

[0009] The purification device is used to purify biomass syngas;

[0010] The dry reforming reaction device is at least provided with a raw material gas inlet and a reformed gas outlet. The purification device is connected to the raw material gas inlet of the dry reforming reaction device, and is used to make the purified biomass syngas undergo dry reforming reaction as part or all of the raw material gas;

[0011] The methanol synthesis reaction device is at least provided with a mixed gas inlet and a product outlet. The reformed gas outlet of the dry reforming reaction device is connected to the mixed gas inlet of the methanol synthesis reaction device; a hydrogen supplementation port is provided on the pipeline connecting the dry reforming reaction device and the methanol synthesis reaction device, and is used to supplement hydrogen to the reformed gas to obtain a mixed gas; the product flowing out from the product outlet of the methanol synthesis reaction device contains methanol.

[0012] According to a specific embodiment of the present invention, preferably, the system further includes: a biomass syngas preparation device, which includes a device for preparing biogas by anaerobic fermentation of biomass; the biomass syngas preparation device is connected to the purification device.

[0013] According to a specific embodiment of the present invention, preferably, the purification device includes a high-temperature dry desulfurization device, etc. More preferably, the high-temperature dry desulfurization device has a pressure maintaining function. Specifically, the pressure maintaining function can be realized by structural units such as a gas distribution component inside the high-temperature dry desulfurization device and / or a pressure stabilizing component provided at the outlet.

[0014] According to a specific embodiment of the present invention, preferably, the pipelines connecting the biomass syngas preparation device and the purification device, and the pipelines connecting the purification device and the dry reforming reaction device are all sealed pipelines, and are respectively provided with pressure regulating devices.

[0015] According to the specific embodiments of the present invention, preferably, an electric heating component is provided in the dry reforming reaction device, and the electric heating component includes one or more of a resistance heating component, an induction heating component, an infrared heating component, etc. By using the electric heating component to provide the heat required for the reaction in the dry reforming reaction device, the present invention can avoid using fuel heating, and thus does not generate additional carbon dioxide emissions.

[0016] According to the specific embodiments of the present invention, preferably, the system further includes: an electrolytic water hydrogen production device connected to the hydrogen supply port. More preferably, the electrolytic water hydrogen production device includes one or more of an alkaline electrolytic cell, a proton exchange membrane electrolytic cell, an alkaline anion exchange membrane electrolytic cell, etc.

[0017] According to the specific embodiments of the present invention, preferably, the system further includes: a heat recovery device disposed between the dry reforming reaction device and the methanol synthesis reaction device and at the front end of the hydrogen supply port for cooling the reformed gas. Specifically, the heat recovery device may include a heat exchanger, such as a waste heat boiler, a gas heat exchanger, etc. The heat exchange medium in the heat exchanger may include water or steam, etc.

[0018] According to the specific embodiments of the present invention, preferably, the heat recovery device is connected to the purification device and the biomass syngas preparation device for using the recovered heat for high-temperature dry desulfurization. Specifically, using the heat recovered by the heat recovery device for high-temperature dry desulfurization is achieved by means of heat exchange. By providing the heat recovery device and using the recovered heat for high-temperature dry desulfurization, the present invention can make full use of the heat of the reformed gas, realize the recovery and utilization of waste heat, and has a good energy-saving effect.

[0019] According to the specific embodiments of the present invention, preferably, the system further includes: a gas compression device disposed between the dry reforming reaction device and the methanol synthesis reaction device and at the rear end of the hydrogen supply port for pressurizing the mixed gas.

[0020] According to the specific embodiments of the present invention, preferably, the system further includes: a gas-liquid separation device and a rectification device; the gas-liquid separation device is connected to the product outlet of the methanol synthesis reaction device for gas-liquid separation of the product of the methanol synthesis reaction to obtain a gas-phase product and a liquid-phase product; the rectification device is connected to the gas-liquid separation device for rectifying the liquid-phase product to obtain a methanol product.

[0021] According to a specific embodiment of the present invention, preferably, the system further comprises: a wastewater circulation pipeline, which is connected to the rectification device and the electrolytic water hydrogen production device, and is used for recycling the wastewater generated by rectifying the liquid-phase product to the electrolytic water hydrogen production as a raw material.

[0022] The present invention realizes the full utilization of resources by using the hydrogen produced by the electrolytic water hydrogen production device as the supplementary hydrogen in the methanol synthesis reaction device and recycling the wastewater generated by rectification to the electrolytic water hydrogen production as a raw material.

[0023] According to a specific embodiment of the present invention, preferably, the system further comprises: a gas-phase product recycling pipeline and a gas-phase product circulation pipeline; the gas-phase product recycling pipeline is connected to the gas-liquid separation device and the dry reforming reaction device, and is used for recycling a part of the gas-phase product obtained by gas-liquid separation to the dry reforming reaction as part of the raw material gas; the gas-phase product circulation pipeline is connected to the gas-liquid separation device and the methanol synthesis reaction device, and is used for returning another part of the gas-phase product obtained by gas-liquid separation as recycle gas to carry out the methanol synthesis reaction. More preferably, a recycle gas flow regulating device is provided on the gas-phase product circulation pipeline. The present invention can realize the maximum utilization of the carbon source by recycling a part of the gas-phase product obtained by gas-liquid separation to the dry reforming reaction device for continuous reaction; by returning another part of the gas-phase product as recycle gas to carry out the methanol synthesis reaction and cooperating with the heat recovery device to cool the reformed gas, the reaction temperature of the methanol synthesis reaction can be controlled.

[0024] The second aspect of the present invention provides a method for producing methanol from a biomass raw material, which is carried out by using the above-mentioned system for producing methanol from a biomass raw material, and the method comprises the following steps:

[0025] Purify the biomass syngas to obtain purified biomass syngas; use the purified biomass syngas as part or all of the raw material gas for dry reforming reaction to obtain reformed gas; supplement hydrogen to the reformed gas to obtain a mixed gas; carry out methanol synthesis reaction on the mixed gas to obtain a product containing methanol.

[0026] According to a specific embodiment of the present invention, preferably, the method further comprises: anaerobically fermenting biomass to obtain the biomass syngas. More preferably, the biomass comprises corn stover. More preferably, the volume percentage content of methane in the biomass syngas is 50-55%, and the volume percentage content of carbon dioxide is 45-50%. The remaining components in the biomass syngas include a small amount of nitrogen and hydrogen sulfide, as well as an even smaller amount of water and oxygen. The strains used for anaerobically fermenting the biomass can be strains in the prior art, and the present invention does not make special restrictions, as long as the biomass syngas with the above methane and carbon dioxide contents can be obtained. Generally, strains such as methanogens are used. In addition, those skilled in the art can understand that the present invention preferably prepares the biomass syngas by anaerobically fermenting the biomass. In this case, the biomass syngas is biogas, or is also called biological biogas.

[0027] According to a specific embodiment of the present invention, preferably, the purification at least includes desulfurization, and the desulfurization method includes high-temperature dry desulfurization. High-temperature dry desulfurization is to remove sulfides (mainly hydrogen sulfide) in the gas using a solid desulfurizer in a high-temperature environment (usually with a temperature higher than 200°C). The present invention does not make special restrictions on the solid desulfurizer used, and solid desulfurizers in the prior art can be used. More preferably, the volume percentage content of hydrogen sulfide in the purified biomass syngas is below 0.1 ppm.

[0028] According to a specific embodiment of the present invention, preferably, the dry reforming reaction is carried out in the presence of a dry reforming catalyst, and the dry reforming catalyst includes one or more of a nickel-based catalyst, a cobalt-based catalyst, a ruthenium-based catalyst, a rhodium-based catalyst, etc. The dry reforming catalyst can be a dry reforming catalyst in the prior art. Specifically, the dry reforming catalyst includes an active component and a carrier; the active component can include one or more of nickel, nickel oxide, cobalt, cobalt oxide, ruthenium, ruthenium oxide, rhodium, and rhodium oxide, etc.; the carrier can include one or more of magnesium oxide, aluminum oxide, cerium oxide, zirconium oxide, and molecular sieve, etc.; based on the total mass of the dry reforming catalyst being 100%, the content of the active component can be 1-20%.

[0029] According to a specific embodiment of the present invention, preferably, the conditions of the dry reforming reaction include: the reaction temperature is 700-950°C, the reaction pressure is 0.1-1.0 MPa, and the space velocity of the raw material gas based on methane is 500-1500 h -1。The pressure for the dry reforming reaction of the present invention can be provided by the device for preparing biogas through anaerobic fermentation of biomass at the front end. By means of the above-mentioned high-temperature dry desulfurization device with a pressure maintenance function, and by using sealed pipelines during the overall transportation process and setting pressure regulating devices on the pipelines, the pressure generated by the anaerobic fermentation of biomass to prepare biogas can be maintained and regulated, so that there is no need to set a booster device in front of the dry reforming reaction device, simplifying the process and reducing the cost.

[0030] In the present invention, the dry reforming reaction does not require additional steam supplementation, and directly uses the purified biomass syngas (preferably the purified biogas) as part or all of the raw material gas for the dry reforming reaction. Since the present invention does not require additional steam supplementation, high-efficiency conversion of carbon dioxide can be achieved under the above process conditions.

[0031] According to a specific embodiment of the present invention, preferably, the method further includes: using a heat recovery device to cool the reformed gas to 200-250°C, and then supplementing hydrogen to the reformed gas. More preferably, the method further includes: using the heat recovered by cooling the reformed gas with a heat recovery device for the high-temperature dry desulfurization.

[0032] According to a specific embodiment of the present invention, preferably, the hydrogen supplemented to the reformed gas is produced by electrolyzing water to produce hydrogen.

[0033] According to a specific embodiment of the present invention, preferably, the method further includes: using a gas compression device to boost the pressure of the mixed gas to 3.0-9.0 MPa, and then carrying out the methanol synthesis reaction on the mixed gas.

[0034] By controlling the temperature of the reformed gas after cooling and the pressure of the mixed gas after boosting within the above ranges, the present invention makes the temperature and pressure suitable for methanol synthesis.

[0035] According to a specific embodiment of the present invention, preferably, the hydrogen-carbon ratio (i.e., H / C molar ratio) in the mixed gas for the methanol synthesis reaction is 2.0-3.0, more preferably 2.0-2.15, and further preferably 2.05-2.10. This hydrogen-carbon ratio can be adjusted through the step of supplementing hydrogen. By controlling the hydrogen-carbon ratio within the above ranges, direct methanol synthesis from the reformed gas can be achieved, greatly simplifying the methanol production process.

[0036] According to a specific embodiment of the present invention, preferably, the methanol synthesis reaction is carried out in the presence of a methanol synthesis catalyst, and the methanol synthesis catalyst includes one or more of a copper-based catalyst, a zinc-zirconium solid solution catalyst, and a noble metal catalyst, etc. The methanol synthesis catalyst can adopt the methanol synthesis catalysts in the prior art.

[0037] According to a specific embodiment of the present invention, preferably, the conditions for the methanol synthesis reaction include: a reaction temperature of 210 - 270 °C, a reaction pressure of 3.0 - 9.0 MPa, and a space velocity of 5000 - 15000 h -1 .

[0038] According to a specific embodiment of the present invention, preferably, the method further includes: separating the product containing methanol into a gas-phase product and a liquid-phase product by gas-liquid separation; rectifying the liquid-phase product to obtain a methanol product. More preferably, the method further includes: recycling the wastewater generated from the rectification of the liquid-phase product to the electrolytic water hydrogen production as a raw material. More preferably, the method further includes: recycling a part of the gas-phase product to the dry reforming reaction as a part of the raw material gas, and returning another part of the gas-phase product as recycle gas to carry out the methanol synthesis reaction. This gas-phase product can also be called purge gas. Further preferably, the volume flow ratio (i.e., the recycle ratio) of the recycle gas to the mixed gas is 2.5 - 5.0. This recycle ratio can be controlled by a recycle gas flow regulating device.

[0039] The present invention cools the reformed gas by using a heat recovery device and controls the recycle ratio within the above range, so that the reaction temperature of the methanol synthesis reaction is controlled at 210 - 270 °C.

[0040] The present invention has at least the following beneficial effects:

[0041] The present invention provides a system and method for producing methanol from biomass raw materials. The present invention uses biomass syngas as a raw material, preferably biogas obtained by anaerobic fermentation as a raw material. After being purified by a purification device, it is then subjected to dry reforming in a dry reforming reaction device. During the dry reforming process, no steam needs to be supplemented. At the same time, preferably, an electric heating method is used to provide the heat required for the reaction. While achieving efficient conversion of carbon dioxide, it also avoids additional carbon dioxide emissions. Subsequently, the present invention preferably uses a heat recovery device to cool the reformed gas containing hydrogen and carbon monoxide to an appropriate temperature, and then mixes it with hydrogen to adjust the hydrogen-carbon ratio. After that, preferably, a gas compression device is used to boost the mixed gas to an appropriate pressure and directly carry out methanol synthesis, greatly simplifying the methanol production process. Then, the present invention preferably separates the gas and liquid and rectifies the product of the methanol synthesis reaction to obtain methanol products. At the same time, the present invention preferably recycles a part of the gaseous product obtained by gas-liquid separation back to the dry reforming reaction as part of the raw material gas, thereby realizing the maximum utilization of the carbon source. In addition, the present invention further preferably recycles the wastewater generated by rectification back to the electrolytic water hydrogen production as a raw material, and uses the heat recovered by the heat recovery device to purify the biomass syngas, realizing the full utilization of resources and waste heat. The present invention greatly simplifies the overall methanol production process, and realizes the efficient conversion of green carbon in biomass syngas, especially biogas, converting most of the carbon into green methanol, with a high carbon utilization rate; and the process of the present invention does not produce additional carbon dioxide emissions, achieving the full-process green production of methanol; and the present invention also realizes the full utilization of materials and waste heat, with good energy-saving effects. Description of the Drawings

[0042] Figure 1 It is a schematic diagram of the system for producing methanol from biomass raw materials in the specific embodiment of the present invention.

[0043] Explanation of the Reference Numerals in the Drawings:

[0044] 1 - Device for preparing biogas by anaerobic fermentation of biomass; 2 - High-temperature dry desulfurization device; 3 - Dry reforming reaction device; 4 - Heat recovery device; 5 - Electrolytic water hydrogen production device; 6 - Gas compression device; 7 - Methanol synthesis reaction device; 8 - Gas-liquid separation device; 9 - Rectification device; 10 - Wastewater circulation pipeline; 11 - Gas-phase product recycling pipeline; 12 - Gas-phase product circulation pipeline; 401 - Waste heat boiler; 402 - Gas heat exchanger. Specific Embodiments

[0045] In order to have a clearer understanding of the technical features, objectives, and beneficial effects of the present invention, the present invention is hereinafter described in detail, but it should not be construed as a limitation on the scope of implementation of the present invention.

[0046] It should be noted that, unless otherwise specified, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention pertains.

[0047] All kinds of raw materials, reagents, instruments, equipment, etc. used in the present invention, unless otherwise specifically stated, can be obtained through market purchase or can be prepared by existing methods.

[0048] It should be understood that the terms "comprising", "including" and / or "containing" when used herein specify the presence of the stated features, integers, steps, components or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, components or combinations thereof.

[0049] In the ranges disclosed in the present invention, the endpoints and any values are not limited to the exact ranges or values. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed in the present invention.

[0050] It should be noted that the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0051] It should be noted that, unless otherwise clearly specified and defined, the terms "installed", "equipped with", "sheathed / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection, can be a mechanical connection, an electrical connection, can be directly connected, or can be indirectly connected through an intermediate medium, and can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0052] Example 1

[0053] This example provides a system for producing methanol from biomass raw materials, as Figure 1 shown, which includes: a device 1 for preparing biogas by anaerobic fermentation of biomass, a high-temperature dry desulfurization device 2, a dry reforming reaction device 3, a heat recovery device 4, an electrolytic water hydrogen production device 5, a gas compression device 6, a methanol synthesis reaction device 7, a gas-liquid separation device 8, a rectification device 9, a wastewater circulation pipeline 10, a gas-phase product reuse pipeline 11, and a gas-phase product circulation pipeline 12;

[0054] The device 1 for preparing biogas by anaerobic fermentation of biomass is connected to the high-temperature dry desulfurization device 2;

[0055] The high-temperature dry desulfurization device 2 is used to purify the biogas prepared by the biogas production device 1 for anaerobic fermentation of biomass, and obtain purified biogas;

[0056] The dry reforming reaction device 3 is at least provided with a raw material gas inlet and a reformed gas outlet. The high-temperature dry desulfurization device 2 is connected to the raw material gas inlet of the dry reforming reaction device 3, and is used to make the purified biogas undergo a dry reforming reaction as part of the raw material gas;

[0057] The methanol synthesis reaction device 7 is at least provided with a mixed gas inlet and a product outlet. The reformed gas outlet of the dry reforming reaction device 3 is connected to the mixed gas inlet of the methanol synthesis reaction device 7; A hydrogen supplement port is arranged on the pipeline connecting the dry reforming reaction device 3 and the methanol synthesis reaction device 7, and is used to supplement hydrogen to the reformed gas to obtain a mixed gas;

[0058] The electrolytic water hydrogen production device 5 is connected to the hydrogen supplement port;

[0059] The heat recovery device 4 is arranged between the dry reforming reaction device 3 and the methanol synthesis reaction device 7, and is arranged at the front end of the hydrogen supplement port, and is used to cool the reformed gas; The heat recovery device 4 is connected to the high-temperature dry desulfurization device 2 and the biogas production device 1 for anaerobic fermentation of biomass, and is used to use the recovered heat for high-temperature dry desulfurization;

[0060] The gas compression device 6 is arranged between the dry reforming reaction device 3 and the methanol synthesis reaction device 7, and is arranged at the rear end of the hydrogen supplement port, and is used to pressurize the mixed gas;

[0061] The gas-liquid separation device 8 is connected to the product outlet of the methanol synthesis reaction device 7, and is used to perform gas-liquid separation on the product of the methanol synthesis reaction to obtain a gas-phase product and a liquid-phase product; The distillation device 9 is connected to the gas-liquid separation device 8, and is used to distill the liquid-phase product to obtain a methanol product;

[0062] The wastewater circulation pipeline 10 is connected to the distillation device 9 and the electrolytic water hydrogen production device 5, and is used to recycle the wastewater generated by distilling the liquid-phase product to the electrolytic water hydrogen production as a raw material;

[0063] The gas-phase product reuse pipeline 11 is connected to the gas-liquid separation device 8 and the dry reforming reaction device 3, and is used to reuse a part of the gas-phase product obtained by gas-liquid separation as part of the raw material gas for the dry reforming reaction; The gas-phase product circulation pipeline 12 is connected to the gas-liquid separation device 8 and the methanol synthesis reaction device 7, and is used to return another part of the gas-phase product obtained by gas-liquid separation as recycle gas for the methanol synthesis reaction.

[0064] Among them, the high-temperature dry desulfurization device 2 has a pressure maintaining function. Specifically, the pressure maintaining function can be realized by structural units such as a gas distribution component inside the high-temperature dry desulfurization device 2 and / or a pressure stabilizing component arranged at the outlet.

[0065] The pipelines connecting the device 1 for preparing biogas by anaerobic fermentation of biomass to the high-temperature dry desulfurization device 2 and the pipelines connecting the high-temperature dry desulfurization device 2 to the dry reforming reaction device 3 are all sealed pipelines, and are respectively provided with pressure regulating devices.

[0066] An electric heating component is arranged in the dry reforming reaction device 3, and the electric heating component includes one or more of a resistance heating component, an induction heating component, an infrared heating component, etc.

[0067] The electrolytic water hydrogen production device 5 includes one or more of an alkaline electrolytic cell, a proton exchange membrane electrolytic cell, an alkaline anion membrane electrolytic cell, etc.

[0068] The heat recovery device 4 includes a waste heat boiler 401 and a gas heat exchanger 402 connected in series, etc. The reformed gas outlet of the dry reforming reaction device 3 is sequentially connected to the waste heat boiler 401 and the gas heat exchanger 402, so as to cool the reformed gas to obtain the cooled reformed gas. The device 1 for preparing biogas by anaerobic fermentation of biomass is connected to the gas heat exchanger 402, so that the biogas exchanges heat with the reformed gas cooled by the waste heat boiler 401 to obtain the heat-exchanged biogas, and the heat-exchanged biogas enters the high-temperature dry desulfurization device 2. The heat exchange medium in the waste heat boiler 401 can include water or steam, etc.

[0069] A circulating gas flow regulating device is arranged on the gas-phase product circulation pipeline 12.

[0070] The method for producing methanol from biomass raw materials using the system of this embodiment includes the following steps:

[0071] The device 1 for preparing biogas by anaerobic fermentation of biomass anaerobically ferments the biomass to obtain biogas; the high-temperature dry desulfurization device 2 is used to perform high-temperature dry desulfurization on the biogas to obtain purified biogas; the purified biogas is used as part of the raw material gas to carry out dry reforming reaction in the dry reforming reaction device 3 to obtain reformed gas; the heat recovery device 4 is used to cool the reformed gas to 200 - 250 °C, and the heat recovered by the heat recovery device 4 is used for high-temperature dry desulfurization to meet the temperature requirement for desulfurization; the electrolytic water hydrogen production device 5 is used to produce hydrogen, and the produced hydrogen is supplemented into the cooled reformed gas to obtain a mixed gas; the gas compression device 6 is used to pressurize the mixed gas to 3.0 - 9.0 MPa; the methanol synthesis reaction device 7 is used to carry out methanol synthesis reaction on the pressurized mixed gas to obtain a product containing methanol; the gas-liquid separation device 8 is used to carry out gas-liquid separation on the product containing methanol to obtain a gas-phase product and a liquid-phase product, a part of the gas-phase product is recycled to the dry reforming reaction as part of the raw material gas, and another part of the gas-phase product is returned as recycle gas to carry out the methanol synthesis reaction; the distillation device 9 is used to distill the liquid-phase product to obtain methanol products, and the wastewater generated by distillation is recycled to the electrolytic water hydrogen production as raw material.

[0072] Among them, the biomass includes corn straw. The volume percentage content of methane in the biomass synthesis gas is 50 - 55%, and the volume percentage content of carbon dioxide is 45 - 50%.

[0073] The volume percentage content of hydrogen sulfide in the purified biogas < 0.1 ppm.

[0074] The dry reforming reaction is carried out in the presence of a dry reforming catalyst. The dry reforming catalyst includes one or more of a nickel-based catalyst, a cobalt-based catalyst, a ruthenium-based catalyst, and a rhodium-based catalyst, etc. Specifically, the dry reforming catalyst includes an active component and a carrier; the active component may include one or more of nickel, nickel oxide, cobalt, cobalt oxide, ruthenium, ruthenium oxide, rhodium, and rhodium oxide, etc.; the carrier may include one or more of magnesium oxide, aluminum oxide, cerium oxide, zirconium oxide, and molecular sieve, etc.; based on the total mass of the dry reforming catalyst being 100%, the content of the active component may be 1 - 20%. The conditions for the dry reforming reaction include: the reaction temperature is 700 - 950 °C, the reaction pressure is 0.1 - 1.0 MPa, and the space velocity of the raw material gas based on methane is 500 - 1500 h -1 。

[0075] The hydrogen-carbon ratio (i.e., H / C molar ratio) in the mixed gas is 2.0 - 2.15, preferably 2.05 - 2.10.

[0076] The methanol synthesis reaction is carried out in the presence of a methanol synthesis catalyst, and the methanol synthesis catalyst includes one or more of a copper-based catalyst, a zinc-zirconium solid solution catalyst, a noble metal catalyst, etc. The conditions for the methanol synthesis reaction include: the reaction temperature is 210 - 270 °C, the reaction pressure is 3.0 - 9.0 MPa, and the space velocity is 5000 - 15000 h -1 .

[0077] The volume flow ratio of the recycle gas to the pressurized mixed gas (i.e., the recycle ratio) is 2.5 - 5.0.

[0078] Example 2

[0079] Using the system and method of Example 1, green methanol is prepared from biogas obtained by anaerobic fermentation through processes such as dry reforming and methanol synthesis. A device 1 for preparing biogas by anaerobic fermentation of biomass is used to anaerobically ferment corn straw to obtain biogas. The flow rate of the biogas is 590 Nm 3 / h, in which the volume content of CH4 is about 55%, the volume content of CO2 is about 45%, the temperature is 40 °C, the pressure is 0.1 MPa, and the sulfur content is 10 ppm. After the biogas is heat-exchanged by the heat recovery device 4, it enters the high-temperature dry desulfurization device 2, and desulfurization is carried out at a temperature of 300 °C to reduce the total sulfur volume content to below 0.1 ppm, obtaining purified biogas. The purified biogas directly enters the dry reforming reaction device 3 and uses a nickel-based catalyst for the dry reforming reaction. The reaction temperature is 900 °C, the reaction pressure is 0.1 MPa, and the space velocity of the raw material gas based on methane is 1000 h -1 , and the dry reforming reaction device 3 is heated using an induction heating component to obtain reformed gas. The gas components of the reformed gas include: the volume content of H2 is about 48%, the volume content of CO is about 47%, the volume content of CO2 is about 2.1%, the volume content of CH4 is about 2%, and the flow rate of the reformed gas is about 1246 Nm 3 / h. The reformed gas is cooled to 200 - 250 °C using the heat recovery device 4. As described above, the heat recovered by the heat recovery device 4 is used to heat-exchange the biogas to meet the temperature for desulfurization. The heat recovery device 4 includes a waste heat boiler 401 and a gas heat exchanger 402 connected in series. Hydrogen is produced using an electrolytic water hydrogen production device 5, and the produced hydrogen is supplemented into the cooled reformed gas to obtain a mixed gas, and the hydrogen-carbon ratio in the mixed gas is 2.05. The flow rate of the supplemented hydrogen is about 597 Nm 3 / h, and the electrolytic water hydrogen production device 5 is an alkaline electrolytic cell hydrogen production device. The mixed gas enters the gas compression device 6 and is compressed to 5.0 MPa, and then enters the methanol synthesis reaction device 7 for the methanol synthesis reaction to obtain a product containing methanol. The methanol synthesis reaction device 7 is filled with a copper-based catalyst, the reaction temperature is 250 °C, the reaction pressure is 5.0 MPa, and the space velocity is 10000 h -1, the recycle ratio is 3.0. The product containing methanol is subjected to gas-liquid separation by the gas-liquid separation device 8 to obtain 767 kg / h of crude methanol (i.e., the liquid-phase product) and purge gas (i.e., the gas-phase product). According to the above recycle ratio, a part of the purge gas is returned as recycle gas for the methanol synthesis reaction, and another part of 120 Nm 3 / h of purge gas is returned to the dry reforming reaction device 3 as part of the feed gas to continue the reaction. The crude methanol is rectified by the rectification device 9 to obtain 709 kg / h of methanol product and 58 kg / h of water, and the water produced by rectification is recycled to the electrolytic water hydrogen production device 5 as the hydrogen production raw material. The overall process carbon yield from biogas to product methanol in this example is 90%.

[0080] Where the methanol carbon yield = (moles of C atoms in methanol ÷ total moles of C atoms in methane and carbon dioxide in biogas) × 100%, the same below.

[0081] Example 3

[0082] Using the system and method of Example 1, green methanol is prepared by processes such as dry reforming and methanol synthesis from biogas obtained by anaerobic fermentation. The device 1 for preparing biogas by biomass anaerobic fermentation is used to anaerobically ferment corn straw to obtain biogas. The flow rate of the biogas is 590 Nm 3 / h, in which the volume content of CH4 is about 55%, the volume content of CO2 is about 45%, the temperature is 40 °C, the pressure is 0.5 MPa, and the sulfur content is 10 ppm. After the biogas is heat-exchanged by the heat recovery device 4, it enters the high-temperature dry desulfurization device 2, and desulfurization is carried out at a temperature of 300 °C to reduce the total sulfur volume content to below 0.1 ppm to obtain purified biogas. The purified biogas directly enters the dry reforming reaction device 3 and uses a nickel-based catalyst for the dry reforming reaction. The reaction temperature is 900 °C, the reaction pressure is 0.5 MPa, and the space velocity of the feed gas based on methane is 1000 h -1 , and the dry reforming reaction device 3 is heated using an induction heating component to obtain reformed gas. The gas components of the reformed gas include: the volume content of H2 is about 47%, the volume content of CO is about 46%, the volume content of CO2 is about 2.5%, the volume content of CH4 is about 2.1%, and the flow rate of the reformed gas is about 1220 Nm 3 / h. The heat recovery device 4 is used to cool the reformed gas to 200 - 250 °C. As described above, the heat recovered by the heat recovery device 4 is used to heat-exchange the biogas to meet the temperature for desulfurization. The heat recovery device 4 includes a waste heat boiler 401 and a gas heat exchanger 402 connected in series. The electrolytic water hydrogen production device 5 is used to produce hydrogen, and the produced hydrogen is supplemented into the cooled reformed gas to obtain a mixed gas, and the hydrogen-carbon ratio in the mixed gas is 2.15. The flow rate of the supplemented hydrogen is about 617 Nm 3 / h, the hydrogen production device 5 by electrolyzing water is an alkaline electrolyzer for hydrogen production. The mixed gas enters the gas compression device 6 and is compressed to 8.0 MPa, then enters the methanol synthesis reaction device 7 for methanol synthesis reaction to obtain a product containing methanol. The methanol synthesis reaction device 7 is filled with a copper-based catalyst, the reaction temperature is 250 °C, the reaction pressure is 8.0 MPa, and the space velocity is 10000 h -1 , and the circulation ratio is 4.0. The product containing methanol is subjected to gas-liquid separation by the gas-liquid separation device 8 to obtain 798 kg / h of crude methanol (i.e., the liquid-phase product) and purge gas (i.e., the gas-phase product). According to the above circulation ratio, a part of the purge gas is returned as recycle gas for methanol synthesis reaction, and another part of 105 Nm 3 / h of purge gas is returned to the dry reforming reaction device 3 as part of the feed gas to continue the reaction. The crude methanol is rectified by the rectification device 9 to obtain 748 kg / h of methanol product and 50 kg / h of water, and the water generated by rectification is recycled to the hydrogen production device 5 by electrolyzing water as the hydrogen production raw material. The overall carbon yield of the whole process of this example from biogas to product methanol is 95%.

[0083] Comparative Example 1

[0084] Adopt the method of producing methanol from biogas in the prior art, and use the biogas obtained by anaerobic fermentation to prepare green methanol through processes such as dry reforming and methanol synthesis. A device for anaerobic fermentation of biomass is used to anaerobically ferment corn straw to obtain biogas. The flow rate of the biogas is 590 Nm 3 / h, in which the volume content of CH4 is about 55%, the volume content of CO2 is about 45%, the temperature is 40 °C, the pressure is 0.8 MPa, and the sulfur content is 10 ppm. After the biogas is heat-exchanged by the heat recovery device, it enters the high-temperature dry desulfurization device and is desulfurized at a temperature of 300 °C to reduce the total sulfur volume content to less than 0.1 ppm to obtain purified biogas. The purified biogas is supplemented with 176 kg / h of steam at 210 °C, and then enters the dry reforming reaction device 3 to carry out the dry reforming reaction using a nickel-based catalyst. The reaction temperature is 900 °C, the reaction pressure is 0.1 MPa, and the space velocity of the feed gas based on methane is 1000 h -1 , and the dry reforming reaction device 3 is heated by an external heat combustion heating method to obtain reformed gas. About 60 Nm 3 / h of natural gas is used for combustion, and about 60 Nm 3 / h of CO2 is discharged. The gas components of the reformed gas include: the volume content of H2 is about 49.2%, the volume content of CO is about 35.1%, the volume content of CO2 is about 5.4%, the volume content of CH4 is about 1.6%, the volume content of water is about 8.7%, and the flow rate of the reformed gas is about 1289 Nm 3 / h. The reformed gas is cooled to 200 °C by a heat recovery device. As described above, the heat recovered by the heat recovery device is used to heat exchange the biogas to meet the temperature for desulfurization. The heat recovery device includes a waste heat boiler and a gas heat exchanger connected in series. Then, the cooled reformed gas is compressed to 5.0 MPa by a gas compression device and then enters a methanol synthesis reaction device for methanol synthesis reaction to obtain a product containing methanol. A copper-based catalyst is loaded in the methanol synthesis reaction device, the reaction temperature is 250 °C, the reaction pressure is 5.0 MPa, and the space velocity is 10000 h -1 , and the recycle ratio is 3.0. The product containing methanol is subjected to gas-liquid separation by a gas-liquid separation device 8 to obtain 694 kg / h of crude methanol (i.e., the liquid-phase product) and purge gas (i.e., the gas-phase product). According to the above recycle ratio, a part of the purge gas is returned as recycle gas for methanol synthesis reaction, and another part of 200 Nm 3 / h of purge gas is returned to the dry reforming reaction device as part of the feed gas for continuous reaction. The crude methanol is rectified by a rectification device to obtain 625 kg / h of methanol product. The overall carbon yield of the process of this comparative example from biogas to product methanol is 86%.

[0085] Comparative Example 2

[0086] It is basically the same as Example 2, except that: hydrogen is not supplemented to the reformed gas. Green methanol is prepared by processes such as dry reforming and methanol synthesis from biogas obtained by anaerobic fermentation. A device for anaerobic fermentation of biomass to produce biogas is used to anaerobically ferment corn straw to obtain biogas. The flow rate of the biogas is 590 Nm 3 / h, in which the volume content of CH4 is about 55%, the volume content of CO2 is about 45%, the temperature is 40 °C, the pressure is 0.1 MPa, and the sulfur content is 10 ppm. After the biogas is heat exchanged by a heat recovery device, it enters a high-temperature dry desulfurization device, and desulfurization is carried out at a temperature of 300 °C to reduce the total sulfur volume content to less than 0.1 ppm to obtain purified biogas. The purified biogas directly enters the dry reforming reaction device and uses a nickel-based catalyst for dry reforming reaction. The reaction temperature is 900 °C, the reaction pressure is 0.1 MPa, and the space velocity of the feed gas based on methane is 1000 h -1 , and the dry reforming reaction device is heated by an induction heating component to obtain reformed gas. The gas components of the reformed gas include: the volume content of H2 is about 48%, the volume content of CO is about 47%, the volume content of CO2 is about 2.1%, the volume content of CH4 is about 2%, and the flow rate of the reformed gas is about 1246 Nm 3 / h. The reformed gas is cooled to 200 - 250 °C by a heat recovery device. As described above, the heat recovered by the heat recovery device is used for heat exchange of biogas to meet the temperature for desulfurization. The heat recovery device includes a waste heat boiler and a gas heat exchanger connected in series. Then, the cooled reformed gas is compressed to 5.0 MPa by a gas compression device and enters a methanol synthesis reaction device for methanol synthesis reaction to obtain a product containing methanol. A copper-based catalyst is loaded in the methanol synthesis reaction device, the reaction temperature is 250 °C, the reaction pressure is 5.0 MPa, and the space velocity is 10000 h -1 , and the recycle ratio is 3.0. The product containing methanol is subjected to gas-liquid separation by a gas-liquid separation device to obtain 690 kg / h of crude methanol (i.e., the liquid-phase product) and purge gas (i.e., the gas-phase product). According to the above recycle ratio, a part of the purge gas is returned as recycle gas for methanol synthesis reaction, and another part of 135 Nm 3 / h of purge gas is returned to the dry reforming reaction device 3 as part of the feed gas for continuous reaction. The crude methanol is rectified by a rectification device to obtain 638 kg / h of methanol product. The overall carbon yield of the process of this comparative example from biogas to product methanol is 84%.

[0087] Comparative Example 3

[0088] It is basically the same as Example 2, except that: the hydrogen-carbon ratio in the mixed gas is different from that in Example 2, and the purge gas from the methanol synthesis reaction is not returned for dry reforming reaction. Green methanol is prepared from biogas obtained by anaerobic fermentation through processes such as dry reforming and methanol synthesis. A device for anaerobic fermentation of biomass to produce biogas is used to anaerobically ferment corn straw to obtain biogas. The flow rate of the biogas is 590 Nm 3 / h, in which the volume content of CH4 is about 55%, the volume content of CO2 is about 45%, the temperature is 40 °C, the pressure is 0.1 MPa, and the sulfur content is 10 ppm. After the biogas is heat-exchanged by a heat recovery device, it enters a high-temperature dry desulfurization device for desulfurization at a temperature of 300 °C, and the total sulfur volume content is reduced to less than 0.1 ppm to obtain purified biogas. The purified biogas directly enters the dry reforming reaction device and uses a nickel-based catalyst for dry reforming reaction. The reaction temperature is 900 °C, the reaction pressure is 0.1 MPa, and the space velocity of the feed gas based on methane is 1000 h -1 , and the dry reforming reaction device is heated by an induction heating component to obtain reformed gas. The gas components of the reformed gas include: the volume content of H2 is about 48%, the volume content of CO is about 47%, the volume content of CO2 is about 2.1%, the volume content of CH4 is about 2%, and the flow rate of the reformed gas is about 1246 Nm 3 / h. The reformed gas is cooled to 200 - 250 °C by a heat recovery device. As described above, the heat recovered by the heat recovery device is used for heat exchange of biogas to meet the temperature requirement for desulfurization. The heat recovery device includes a waste heat boiler and a gas heat exchanger connected in series. Hydrogen is produced by an electrolytic water hydrogen production device, and the produced hydrogen is supplemented into the cooled reformed gas to obtain a mixed gas with a hydrogen-carbon ratio of 1.5. The flow rate of the supplemented hydrogen is about 280 Nm 3 / h, and the electrolytic water hydrogen production device is an alkaline electrolytic cell hydrogen production device. The mixed gas enters a gas compression device and is compressed to 5.0 MPa, then enters a methanol synthesis reaction device for methanol synthesis reaction to obtain a product containing methanol. The methanol synthesis reaction device is filled with a copper-based catalyst, the reaction temperature is 250 °C, the reaction pressure is 5.0 MPa, and the space velocity is 10,000 h -1 , and the recycle ratio is 3.0. The product containing methanol is subjected to gas-liquid separation by a gas-liquid separation device 8 to obtain 728 kg / h of crude methanol (i.e., the liquid-phase product) and purge gas (i.e., the gas-phase product). According to the above recycle ratio, a part of the purge gas is returned as recycle gas for methanol synthesis reaction, resulting in a purge gas emission of 130 Nm 3 / h. The crude methanol is rectified by a rectification device 9 to obtain 673 kg / h of methanol product and 55 kg / h of water, and the water produced by rectification is recycled to the electrolytic water hydrogen production device 5 as a hydrogen production raw material. The overall carbon yield of the present comparative example from biogas to product methanol is 86%.

[0089] It can be seen from the above embodiments and comparative examples that the embodiments of the present invention simplify the overall production process of methanol greatly through process routes such as direct biogas reforming by electric heating, adjusting the hydrogen-carbon ratio by hydrogen supplementation in the reformed gas, and returning the purge gas from the methanol synthesis reaction for dry reforming reaction. Moreover, it realizes the efficient conversion of green carbon in biogas, converts most of the carbon into green methanol, and has a high carbon utilization rate; and no additional carbon dioxide emissions are generated during the process, achieving the green production of methanol throughout the process; and it also realizes the full utilization of materials and waste heat, having a good energy-saving effect. While using the same catalyst as in the embodiment, Comparative Example 1 adopts the method of producing methanol from biogas in the prior art, its carbon utilization rate is significantly lower than that of the embodiment, and a large amount of carbon dioxide emissions are generated; the carbon utilization rate of Comparative Example 2 is also significantly lower than that of the embodiment; not only is the carbon utilization rate of Comparative Example 3 lower than that of the embodiment, but also a large amount of purge gas emissions are generated.

[0090] The specific embodiments described above further elaborate the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A system for producing methanol from biomass raw materials, comprising: Purification unit, dry reforming reaction unit and methanol synthesis reaction unit; The purification device is used to purify biomass synthesis gas; The dry reforming reaction device is at least provided with a raw gas inlet and a reformed gas outlet, and the purification device is connected to the raw gas inlet of the dry reforming reaction device, and is used to use the purified biomass synthesis gas as part or all of the raw gas for dry reforming reaction; The methanol synthesis reaction device is at least provided with a mixed gas inlet and a product outlet, and the reformed gas outlet of the dry reforming reaction device is connected to the mixed gas inlet of the methanol synthesis reaction device; a hydrogen replenishing port is provided on the pipeline connecting the dry reforming reaction device and the methanol synthesis reaction device, which is used to replenish hydrogen into the reformed gas to obtain a mixed gas; the product flowing out of the product outlet of the methanol synthesis reaction device contains methanol.

2. The system for producing methanol from biomass raw materials according to claim 1, wherein: The system further comprises: a biomass synthesis gas preparation device, which comprises a device for preparing biogas by anaerobic fermentation of biomass; the biomass synthesis gas preparation device is connected to the purification device; Preferably, the purification device comprises a high-temperature dry desulfurization device; more preferably, the high-temperature dry desulfurization device has a pressure maintenance function; Preferably, the dry reforming reaction device is provided with an electric heating component, and the electric heating component includes one or more of a resistance heating component, an induction heating component and an infrared heating component.

3. The system for producing methanol from biomass raw materials according to claim 1, wherein: The system further comprises: a water electrolysis hydrogen production device connected to the hydrogen replenishment port; Preferably, the water electrolysis hydrogen production device comprises one or more of an alkaline electrolyzer, a proton exchange membrane electrolyzer and an alkaline anion membrane electrolyzer.

4. The system for producing methanol from biomass raw materials according to claim 2, wherein: The system further comprises: a heat recovery device, which is arranged between the dry reforming reaction device and the methanol synthesis reaction device and arranged at the front end of the hydrogen replenishment port, and is used to cool the reformed gas; Preferably, the heat recovery device is connected to the purification device and the biomass synthesis gas preparation device, and is used to use the recovered heat for high-temperature dry desulfurization.

5. The system for producing methanol from biomass raw materials according to claim 3, wherein: The system further comprises: a gas compression device, which is arranged between the dry reforming reaction device and the methanol synthesis reaction device and arranged at the rear end of the hydrogen replenishment port, and is used to pressurize the mixed gas; Preferably, the system further comprises: a gas-liquid separation device and a distillation device; the gas-liquid separation device is connected to the product outlet of the methanol synthesis reaction device, and is used to perform gas-liquid separation on the product of the methanol synthesis reaction to obtain a gas phase product and a liquid phase product; the distillation device is connected to the gas-liquid separation device, and is used to perform distillation on the liquid phase product to obtain a methanol product; Preferably, the system further comprises: a wastewater circulation pipeline connected to the distillation device and the water electrolysis hydrogen production device, for recycling the wastewater generated by distilling the liquid phase product to the water electrolysis hydrogen production as a raw material; Preferably, the system further comprises: a gas product recycling pipeline and a gas product circulation pipeline; the gas product recycling pipeline is connected to the gas-liquid separation device and the dry reforming reaction device, and is used to recycle a part of the gas product obtained by gas-liquid separation to the dry reforming reaction as part of the raw gas; the gas product circulation pipeline is connected to the gas-liquid separation device and the methanol synthesis reaction device, and is used to return another part of the gas product obtained by gas-liquid separation as circulating gas to the methanol synthesis reaction.

6. A method for producing methanol from biomass raw materials, which is carried out using the system for producing methanol from biomass raw materials according to any one of claims 1 to 5, and the method comprises the following steps: The biomass synthesis gas is purified to obtain purified biomass synthesis gas; the purified biomass synthesis gas is used as part or all of the raw gas for dry reforming reaction to obtain reformed gas; hydrogen is added to the reformed gas to obtain a mixed gas; the mixed gas is subjected to a methanol synthesis reaction to obtain a product containing methanol.

7. The method for producing methanol from biomass raw materials according to claim 6, wherein: The method further comprises: performing anaerobic fermentation on the biomass to obtain the biomass syngas; Preferably, the biomass comprises corn stover; Preferably, the volume percentage of methane in the biomass synthesis gas is 50-55%, and the volume percentage of carbon dioxide is 45-50%.

8. The method for producing methanol from biomass raw materials according to claim 6, wherein: The purification includes at least desulfurization, and the desulfurization method includes high-temperature dry desulfurization; Preferably, the volume percentage of hydrogen sulfide in the purified biomass synthesis gas is less than 0.1 ppm.

9. The method for producing methanol from biomass raw materials according to claim 6, wherein: The dry reforming reaction is carried out in the presence of a dry reforming catalyst, wherein the dry reforming catalyst includes one or more of a nickel-based catalyst, a cobalt-based catalyst, a ruthenium-based catalyst and a rhodium-based catalyst; Preferably, the conditions of the dry reforming reaction include: a reaction temperature of 700-950°C, a reaction pressure of 0.1-1.0 MPa, and a space velocity of 500-1500 h / min in terms of methane. -1 .

10. The method for producing methanol from biomass raw materials according to claim 8, wherein: The method further comprises: using a heat recovery device to cool the reformed gas to 200-250° C., and then adding hydrogen to the reformed gas; Preferably, the method further comprises: using a heat recovery device to cool the reformed gas so as to recover heat for the high-temperature dry desulfurization.

11. The method for producing methanol from biomass raw materials according to claim 6, wherein: The hydrogen added to the reformed gas is produced by electrolyzing water.

12. The method for producing methanol from biomass raw materials according to claim 6, wherein: The method further comprises: using a gas compression device to pressurize the mixed gas to 3.0-9.0 MPa, and then subjecting the mixed gas to a methanol synthesis reaction.

13. The method for producing methanol from biomass raw materials according to claim 6, wherein: The hydrogen-to-carbon ratio in the mixed gas for methanol synthesis reaction is 2.0-3.0; Preferably, the methanol synthesis reaction is carried out in the presence of a methanol synthesis catalyst, wherein the methanol synthesis catalyst comprises one or more of a copper-based catalyst, a zinc-zirconium solid solution catalyst and a noble metal catalyst; Preferably, the conditions for the methanol synthesis reaction include: reaction temperature of 210-270°C, reaction pressure of 3.0-9.0 MPa, and space velocity of 5000-15000 h -1 .

14. The method for producing methanol from biomass raw materials according to claim 11, wherein: The method further comprises: performing gas-liquid separation on the product containing methanol to obtain a gas phase product and a liquid phase product; performing rectification on the liquid phase product to obtain a methanol product; Preferably, the method further comprises: recycling the wastewater generated by distilling the liquid phase product to electrolyze water to produce hydrogen as a raw material; Preferably, the method further comprises: recycling a portion of the gaseous product to the dry reforming reaction as part of the feed gas, and returning another portion of the gaseous product as the circulating gas to the methanol synthesis reaction; more preferably, the ratio of the volume flow of the circulating gas to the mixed gas is 2.5-5.0.

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