System for efficiently utilizing biochar and wood vinegar to prepare green methanol
Preparation of green methanol through biomass pyrolysis and synthesis gas regulation solves the problems of high energy consumption and large carbon emissions in traditional methanol synthesis, and achieves efficient and environmentally friendly biomass resource utilization and green methanol production.
Patent Information
- Application Number
- CN202410053992.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-12
- Publication Date
- 2025-07-25
AI Technical Summary
In the prior art, traditional methanol synthesis processes have high energy consumption, large carbon emissions, serious environmental pollution, and the hydrogen-carbon molar ratio is difficult to reach the theoretical ratio of methanol synthesis, which affects process efficiency.
By combining biomass thermal cracking unit, synthesis gas preparation unit, hydrogen-carbon ratio adjustment unit and green methanol synthesis unit, green methanol synthesis unit is used to prepare green methanol by using biochar and wood vinegar liquid to adjust the proportion of hydrogen-carbon components in the synthesis gas, and achieve self-circulation and efficient conversion of carbon and hydrogen.
It has achieved efficient conversion of biomass into green methanol, high carbon source utilization rate, carbon neutral process, reduced carbon emissions, protected the environment, and met green energy needs.
Smart Images
Figure CN120361824A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of clean energy preparation, and particularly relates to a system for efficiently producing green methanol by using biochar and wood vinegar liquid. Background Art
[0002] Energy is the foundation of national economy and social development. With the rapid development of the global economy, energy shortage has become an urgent problem that needs to be solved by all countries, and it has gradually become a bottleneck restricting the current and future development of our country. The ecological environmental pollution problems caused by the development and utilization of traditional energy are becoming increasingly serious. Therefore, the research on efficiently preparing green energy, alleviating the pressure of energy demand, improving the ecological system environment, and at the same time ensuring the regional economic development has important scientific, economic and social significance.
[0003] Methanol fuel is the simplest liquid fuel that can be synthesized on a large scale industrially. Industrially, methanol is mainly synthesized by the method of catalytic hydrogenation of carbon monoxide under pressure. The process includes gas generation, synthesis purification, methanol synthesis, and crude methanol rectification and other processes. Although this process is relatively mature, its gas generation process requires high energy consumption and a large amount of fossil fuels such as coal, petroleum or natural gas. With the continuous consumption of fossil fuels, not only will the process cost become higher and higher, but also a large amount of greenhouse gas CO2 will be released during the methanol synthesis process, and its carbon emission intensity is even higher than that of traditional fuels, seriously polluting the environment. Summary of the Invention
[0004] The purpose of the present invention is to overcome the above-mentioned defects existing in the prior art, and provide a system for efficiently producing green methanol by using biochar and wood vinegar liquid. By combining a biomass pyrolysis unit, a syngas preparation unit, a hydrogen-carbon ratio adjustment unit, and a green methanol synthesis unit, it can effectively and efficiently, stably and economically convert the wood vinegar liquid and biochar generated by biomass pyrolysis into green methanol.
[0005] The present invention provides a system for efficiently utilizing biochar and wood vinegar to produce green methanol, the system comprising a biomass thermal cracking unit, a synthesis gas preparation unit, a hydrogen-carbon ratio adjustment unit and a green methanol synthesis unit; biomass is transported to the biomass thermal cracking unit for pyrolysis reaction, and solid-liquid separation is performed after the reaction to obtain biochar and wood vinegar; the biochar and the wood vinegar are transported to the synthesis gas preparation unit for water-gas reaction to obtain synthesis gas and co-produced by-products; the synthesis gas comprises one or more of CO, CO2, H2 and CH4; the co-produced by-products It comprises one or more of activated biochar, aldehydes, ketones and acids; the synthesis gas is sent to the hydrogen-carbon ratio adjustment unit to adjust the ratio between the hydrogen and carbon components in the synthesis gas to meet the stoichiometric hydrogen-carbon molar ratio f=2.05-2.15 required for the green methanol synthesis reaction; the synthesis gas meeting the hydrogen-carbon molar ratio f=2.05-2.15 is sent to the green methanol synthesis unit, and a methanol synthesis reaction is carried out with CO, CO2 and H2 in the synthesis gas as raw materials to obtain green methanol; the carbon atoms and hydrogen atoms in the green methanol all come from the biomass.
[0006] Optionally, the hydrogen-to-carbon ratio adjustment unit includes one or more of a green hydrogen supplementation process, a membrane separation process, a pressure swing adsorption process, a dry reforming process and a carbon supplementation process.
[0007] Optionally, if the molar ratio of H2 to CO in the synthesis gas is lower than 2:1, adjusting the ratio between the hydrogen and carbon components in the synthesis gas specifically includes the following steps: converting the CH4 in the synthesis gas into H2 and CO using the dry reforming process, then separating CO using the membrane separation technology or the pressure swing adsorption technology, and introducing H2 using the green hydrogen supplementation process, so that the molar ratio of H2 to CO in the synthesis gas meets 2:1.
[0008] Optionally, if the molar ratio of H2 to CO in the synthesis gas is higher than 2:1, adjusting the ratio between the hydrogen and carbon components in the synthesis gas specifically includes the following steps: converting the CH4 in the synthesis gas into H2 and CO using the dry reforming process, and then separating the H2 using the membrane separation technology or the pressure swing adsorption technology to make the molar ratio of H2 to CO in the synthesis gas meet 2:1; storing the separated H2 for use as green hydrogen reserve.
[0009] Optionally, if the molar ratio of H2 to CO2 in the synthesis gas is lower than 3:1, adjusting the ratio between hydrogen and carbon components in the synthesis gas specifically includes the following steps: separating CO2 using the membrane separation technology or the pressure swing adsorption technology, and introducing H2 using the green hydrogen supplementation process, so that the molar ratio of H2 to CO2 in the synthesis gas meets 3:1.
[0010] Optionally, when the molar ratio of H2 to CO2 in the syngas is higher than 3:1, adjusting the ratio between the hydrogen and carbon components in the syngas specifically includes the following steps: introducing CO2 captured by a carbon capture system powered by green electricity for supplementation to make the molar ratio of H2 to CO2 in the syngas meet 3:1.
[0011] Optionally, the system further includes separating CO2 and H2O by gas-liquid separation after the combustion reaction of the green methanol for recycling; inputting the CO2 separated by gas-liquid separation into the hydrogen-carbon adjustment unit as syngas for recycling; and inputting the H2O separated by gas-liquid separation into the biomass pyrolysis unit as pyrolysis raw materials for recycling.
[0012] Optionally, the biomass includes one or more of agricultural and forestry wastes, domestic garbage, and municipal sludge; the mass ratio of the biochar to the biomass is (0.2 - 0.5):1.
[0013] Optionally, the temperature of the pyrolysis reaction is 350°C - 950°C; the time of the pyrolysis reaction is 10 min - 30 min; the temperature of the water-gas reaction is 350°C - 1000°C; the time of the water-gas reaction is 1 s - 3 h.
[0014] Optionally, the energy sources used in the system are all green electricity and biomass energy; in the biomass pyrolysis unit, it also includes standing, sedimentation, and centrifugation of the wood vinegar liquid obtained after solid-liquid separation to obtain purified wood vinegar liquid.
[0015] Compared with the prior art, the beneficial effects of the present invention:
[0016] Compared with the traditional processes for producing methanol from coal and natural gas, the present invention provides a system for efficiently producing green methanol from biochar and wood vinegar. By combining a biomass pyrolysis unit, a syngas preparation unit, a hydrogen-carbon ratio adjustment unit, and a green methanol synthesis unit, it can effectively and efficiently, stably, and economically convert the wood vinegar and biochar produced by biomass pyrolysis into green methanol. Among them, the biochar and wood vinegar used in this system are both from biomass pyrolysis, finding a more valuable practical application means for biomass pyrolysis products, realizing the comprehensive and efficient utilization of biomass. While meeting the development needs of green energy, the carbon atoms and hydrogen atoms in the obtained green methanol all come from biochar. The carbon atoms in biochar come from CO2 in the air, and the CO2 and H2O generated by the combustion of green methanol can be used as syngas and pyrolysis raw materials respectively for recycling, realizing the carbon-hydrogen self-circulation. There is no new carbon emission in the whole process, which is carbon-neutral, has a very high carbon source utilization rate, can relieve the energy crisis, reduce air pollution, and protect the environment. On this basis, the present invention also solves the problem that the hydrogen-carbon molar ratio in traditional pyrolysis gas production cannot reach the theoretical ratio for methanol synthesis through the set hydrogen-carbon ratio adjustment unit. By adjusting the gas ratio, syngas with a hydrogen-carbon molar ratio meeting the requirements can be directly obtained, realizing the complete conversion of all components and not causing "hydrogen deficiency or carbon deficiency" to affect the overall process. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 It is a flow chart of the system for efficiently producing green methanol from biochar and wood vinegar according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0018] The following further illustrates the present invention with specific embodiments, but does not limit the present invention in any way.
[0019] The present invention discloses a system for efficiently producing green methanol from biochar and wood vinegar. As Figure 1 shown, Figure 1 It is a flow chart of the system for efficiently producing green methanol from biochar and wood vinegar according to an embodiment of the present invention. The system includes a biomass pyrolysis unit, a syngas preparation unit, a hydrogen-carbon ratio adjustment unit, and a green methanol synthesis unit.
[0020] Further, the biomass is transported to the biomass pyrolysis unit for pyrolysis reaction, and after the reaction, solid-liquid separation is carried out to obtain biochar and wood vinegar.
[0021] Specifically, the biomass pyrolysis forms liquid-solid products, where the liquid-phase product is wood vinegar and the solid-phase product is biochar. Among them, wood vinegar mainly includes a large amount of water, as well as organic acids, aldehydes, ketones, furan substances, phenol substances, and macromolecular oligomers.
[0022] Based on the above, in a specific embodiment, the biomass pyrolysis unit further includes allowing the wood vinegar obtained after solid-liquid separation to stand, precipitate, and centrifuge to obtain purified wood vinegar, so as to improve the yield and purity of green methanol.
[0023] In a specific embodiment, the biomass includes one or more of agricultural and forestry waste, domestic waste, and municipal sludge.
[0024] In a specific embodiment, the temperature of the pyrolysis reaction is 350°C to 950°C; the time of the pyrolysis reaction is 10 min to 30 min.
[0025] In a specific embodiment, a carrier gas can be introduced during the pyrolysis reaction, and the carrier gas is one or several of nitrogen and inert gases, and the inert gas is one or several of helium, neon, argon, krypton, and xenon.
[0026] In a specific embodiment, the mass ratio of biochar to biomass is (0.2 to 0.5):1.
[0027] In a specific embodiment, the pyrolysis treatment is preferably carried out in a conventional pyrolysis device.
[0028] In a specific embodiment, the present invention does not have any special limitations on solid-liquid separation, and the process well-known to those skilled in the art can be used.
[0029] Furthermore, the biochar and wood vinegar are transported to the syngas preparation unit for a water gas reaction to obtain syngas and co-produced by-products; the syngas includes one or more of CO, CO2, H2, and CH4; the co-produced by-products include one or more of activated biochar, aldehydes, ketones, and acids.
[0030] Specifically, the reaction formulas for preparing syngas by the water gas reaction using biochar and wood vinegar as raw materials are shown in (1) and (2) respectively:
[0031] (1) C + H2O → H2 + CO;
[0032] (2) C + 2H2O → 2H2 + CO2;
[0033] In a specific embodiment, the temperature of the water gas reaction is 350°C to 1000°C; the time of the water gas reaction is 1 s to 3 h.
[0034] In a specific embodiment, the co-produced by-products can be treated by a conventional post-treatment method and reused as chemical raw materials.
[0035] In a specific embodiment, the conventional post-treatment method can include a combination of multi-stage condensation, gas separation, and gas adsorption to separate and purify the above co-produced by-products.
[0036] Further, the syngas is transported to the green methanol synthesis unit, and methanol synthesis reaction is carried out using CO, CO2 and H2 in the syngas as raw materials to obtain green methanol; both carbon atoms and hydrogen atoms in the green methanol are from biomass.
[0037] Specifically, the reaction formulas for preparing green methanol using CO, CO2 and H2 as raw materials are shown in (1) and (2) respectively:
[0038] (1) CO + 2H2 → CH3OH;
[0039] (2) CO2 + 3H2 → CH3OH + H2O;
[0040] It can be seen from the above reaction formulas (1) and (2) that a large amount of hydrogen is required for subsequent green methanol synthesis. Therefore, further, the system also includes a hydrogen-carbon ratio adjustment unit arranged between the syngas preparation unit and the green methanol synthesis unit to adjust the ratio between hydrogen and carbon components in the syngas to meet the requirement of the stoichiometric hydrogen-carbon molar ratio f = 2.05 - 2.15 required for the green methanol synthesis reaction, so as to solve the problem that the hydrogen-carbon molar ratio in traditional pyrolysis gas production cannot reach the theoretical ratio of methanol synthesis, directly obtain syngas with a hydrogen-carbon molar ratio meeting the requirements by adjusting the gas ratio, achieve complete conversion of all components, and will not cause "hydrogen deficiency or carbon deficiency" to affect the performance of the overall process, ensuring a high yield of green methanol.
[0041] In a specific embodiment, the hydrogen-carbon ratio adjustment unit includes one or more of a green hydrogen supplementation process, a membrane separation process, a pressure swing adsorption process, a dry reforming process, and a carbon supplementation process.
[0042] In a specific embodiment, when the H2 / CO molar ratio in the syngas is lower than 2:1, adjusting the ratio between hydrogen and carbon components in the syngas specifically includes the following steps: converting CH4 in the syngas into H2 and CO using the dry reforming process, then separating CO using the membrane separation technology or the pressure swing adsorption technology, and introducing H2 using the green hydrogen supplementation process to make the H2 / CO molar ratio in the syngas meet 2:1.
[0043] In a specific embodiment, when the H2 / CO molar ratio in the syngas is higher than 2:1, adjusting the ratio between hydrogen and carbon components in the syngas specifically includes the following steps: converting CH4 in the syngas into H2 and CO using the dry reforming process, then separating H2 using the membrane separation technology or the pressure swing adsorption technology to make the H2 / CO molar ratio in the syngas meet 2:1.
[0044] In a specific embodiment, the separated H2 is stored and can be used as backup green hydrogen. Based on this, the embodiment of the present invention can also be provided with a hydrogen storage unit, in which the separated H2 is stored and H2 is input into the green methanol synthesis unit to ensure continuous and stable input of H2 into the subsequent green methanol synthesis unit.
[0045] In a specific embodiment, when the molar ratio of H2 to CO2 in the syngas is lower than 3:1, adjusting the ratio between the hydrogen and carbon components in the syngas specifically includes the following steps: separating CO2 by membrane separation technology or pressure swing adsorption technology, and introducing H2 by the green hydrogen supplementation process to make the molar ratio of H2 to CO2 in the syngas meet 3:1.
[0046] In a specific embodiment, when the molar ratio of H2 to CO2 in the syngas is higher than 3:1, adjusting the ratio between the hydrogen and carbon components in the syngas specifically includes the following steps: introducing the CO2 captured by the carbon capture system powered by green electricity for supplementation to make the molar ratio of H2 to CO2 in the syngas meet 3:1.
[0047] In a specific embodiment, the system also includes separating CO2 and H2O by gas-liquid separation after the combustion reaction of green methanol for recycling; inputting the CO2 separated by gas-liquid separation into the hydrogen-carbon adjustment unit as syngas for recycling; and inputting the H2O separated by gas-liquid separation into the biomass pyrolysis unit as pyrolysis raw materials for recycling. Specifically, the biochar and wood vinegar liquid used in the system both come from biomass pyrolysis, finding a more valuable practical application means for biomass pyrolysis products, realizing the comprehensive and efficient utilization of biomass. While meeting the development needs of green energy, the carbon atoms and hydrogen atoms in the obtained green methanol both come from biochar, the carbon atoms in biochar come from CO2 in the air, and the CO2 generated by the combustion of green methanol can be used as syngas for recycling. No new carbon emissions are added in the whole process, which is carbon-neutral, has a very high carbon source utilization rate, can relieve the energy crisis, reduce air pollution, protect the environment. At the same time, the H2O generated by the combustion of green methanol is input into the biomass pyrolysis unit as pyrolysis raw materials for recycling, realizing the carbon-hydrogen self-circulation.
[0048] In a specific embodiment, the energy used by the system is all green electricity and biomass energy.
[0049] The following are specific embodiments
[0050] Example 1
[0051] The high-efficiency biochar and wood vinegar liquid utilization system for producing green methanol in this embodiment includes a biomass pyrolysis unit, a syngas preparation unit, a green methanol synthesis unit, and a hydrogen-carbon ratio adjustment unit.
[0052] 1) The straw is transported to the biomass pyrolysis unit for pyrolysis reaction at 650 °C. After the reaction, solid-liquid separation is carried out to obtain biochar and wood vinegar liquid.
[0053] 2) The obtained biochar and wood vinegar liquid are transported to the syngas preparation unit for water-gas reaction at 750 °C for 3 h. The reaction equations are shown in (1) and (2) respectively. The chemical composition of the obtained syngas is shown in Table 1:
[0054] (1) C + H2O → H2 + CO;
[0055] (2) C + 2H2O → 2H2 + CO2;
[0056] Table 1 Analysis data of gas volume percentage
[0057] <![CDATA[H2%]]> CO% <![CDATA[CH4%]]> <![CDATA[CO2%]]> 22 52 9 17
[0058] 3) And through the hydrogen-carbon ratio adjustment unit to adjust the ratio between hydrogen and carbon components in the syngas to meet the requirement of the stoichiometric hydrogen-carbon molar ratio f = 2.05 - 2.15 required for the green methanol synthesis reaction. If the molar ratio of H2 to CO in the syngas is lower than 2:1, the CH4 in the syngas is converted into H2 and CO by the dry reforming process, and then CO is separated by the membrane separation technology or pressure swing adsorption technology, and H2 is introduced by the green hydrogen supplementation process; if the molar ratio of H2 to CO in the syngas is higher than 2:1, the CH4 in the syngas is converted into H2 and CO by the dry reforming process, and then H2 is separated by the membrane separation technology or pressure swing adsorption technology; if the molar ratio of H2 to CO2 in the syngas is lower than 3:1, CO2 is separated by the membrane separation technology or pressure swing adsorption technology, and H2 is introduced by the green hydrogen supplementation process; if the molar ratio of H2 to CO2 in the syngas is higher than 3:1, CO2 captured by the carbon capture system powered by green electricity is introduced for supplementation.
[0059] 4) The obtained CO, CO2 and H2 are transported to the green methanol synthesis unit for methanol synthesis reaction to obtain green methanol. The reaction equations are shown in (1) and (2) respectively:
[0060] (1) CO + 2H2 → CH3OH;
[0061] (2) CO2 + 3H2 → CH3OH + H2O;
[0062] In summary, the present invention provides a system for efficiently utilizing biochar and wood vinegar liquid to produce green methanol. By combining the biomass pyrolysis unit, the syngas preparation unit and the green methanol synthesis unit, the wood vinegar liquid and biochar produced by biomass pyrolysis can be effectively, efficiently, stably and economically converted into green methanol, and one ton of biochar can be converted into 0.1 ton to 0.5 ton of green methanol.
[0063] The embodiments described above merely represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation to the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.
Claims
1. An efficient system for producing green methanol by utilizing biochar and wood vinegar, characterized in that, The system includes a biomass pyrolysis unit, a syngas preparation unit, a hydrogen-carbon ratio adjustment unit, and a green methanol synthesis unit; The biomass is transported to the biomass pyrolysis unit for pyrolysis reaction, and after the reaction, solid-liquid separation is carried out to obtain biochar and wood vinegar liquid; The biochar and the wood vinegar liquid are transported to the syngas preparation unit for water-gas reaction to obtain syngas and co-produced by-products; the syngas includes one or more of CO, CO2, H2, and CH4; the co-produced by-products include one or more of activated biochar, aldehydes, ketones, and acids; The syngas is sent to the hydrogen-carbon ratio adjustment unit to adjust the ratio between the hydrogen and carbon components in the syngas to meet the requirement of the stoichiometric hydrogen-carbon molar ratio f = 2.05 - 2.15 required for the green methanol synthesis reaction; The syngas meeting the hydrogen-carbon molar ratio f = 2.05 - 2.15 is transported to the green methanol synthesis unit, and methanol synthesis reaction is carried out using CO, CO2, and H2 in the syngas as raw materials to obtain green methanol; both carbon atoms and hydrogen atoms in the green methanol come from the biomass.
2. The green methanol production system for efficiently utilizing biochar and wood vinegar liquid according to claim 1, wherein The hydrogen-carbon ratio adjustment unit includes one or more of a green hydrogen supplementation process, a membrane separation process, a pressure swing adsorption process, a dry reforming process, and a carbon supplementation process.
3. The green methanol production system for efficiently utilizing biochar and wood vinegar according to claim 2, wherein When the molar ratio of H2 to CO in the syngas is lower than 2:1, adjusting the ratio between the hydrogen and carbon components in the syngas specifically includes the following steps: After converting CH4 in the syngas into H2 and CO using the dry reforming process, separating CO using the membrane separation technology or the pressure swing adsorption technology, and introducing H2 using the green hydrogen supplementation process, so that the molar ratio of H2 to CO in the syngas meets 2:
1.
4. The green methanol production system for efficiently utilizing biochar and wood vinegar liquid according to claim 2, wherein When the molar ratio of H2 to CO in the syngas is higher than 2:1, adjusting the ratio between the hydrogen and carbon components in the syngas specifically includes the following steps: After converting CH4 in the syngas into H2 and CO using the dry reforming process, separating H2 using the membrane separation technology or the pressure swing adsorption technology, so that the molar ratio of H2 to CO in the syngas meets 2:1; storing the separated H2, which can be used as standby green hydrogen.
5. The green methanol production system for efficiently utilizing biochar and wood vinegar according to claim 2, wherein When the molar ratio of H2 to CO2 in the syngas is lower than 3:1, adjusting the ratio between the hydrogen and carbon components in the syngas specifically includes the following steps: Separating CO2 using the membrane separation technology or the pressure swing adsorption technology, and introducing H2 using the green hydrogen supplementation process, so that the molar ratio of H2 to CO2 in the syngas meets 3:
1.
6. The green methanol production system using biochar and wood vinegar efficiently according to claim 2, characterized in that, When the molar ratio of H2 to CO2 in the syngas is higher than 3:1, adjusting the ratio between the hydrogen and carbon components in the syngas specifically includes the following steps: Introducing CO2 captured by a carbon capture system powered by green electricity for supplementation, so that the molar ratio of H2 to CO2 in the syngas meets 3:
1.
7. The green methanol production system for efficiently utilizing biochar and wood vinegar according to claim 1, characterized in that, The system further includes burning the green methanol and separating CO2 and H2O through gas-liquid separation after the reaction for recycling; Inputting the CO2 separated through gas-liquid separation into the hydrogen-carbon adjustment unit as syngas for recycling; Inputting the H2O separated through gas-liquid separation into the biomass pyrolysis unit as pyrolysis raw material for recycling.
8. The green methanol production system for efficiently utilizing biochar and wood vinegar according to claim 1, wherein The biomass includes one or more of agricultural and forestry wastes, domestic garbage, and municipal sludge; The mass ratio of the biochar to the biomass is (0.2 - 0.5):
1.
9. The green methanol production system using biochar and wood vinegar liquid efficiently according to claim 1, characterized in that, The temperature of the pyrolysis reaction is 350°C - 950°C; The time of the pyrolysis reaction is 10 min - 30 min; The temperature of the water-gas reaction is 350°C - 1000°C; The time of the water-gas reaction is 1 s - 3 h.
10. The green methanol production system using biochar and wood vinegar liquid efficiently according to claim 1, characterized in that The energy used in the system is all green electricity and biomass energy; In the biomass pyrolysis unit, it also includes standing, precipitation, and centrifugation of the wood vinegar obtained after solid-liquid separation to obtain purified wood vinegar.