Method for synergistically producing hard carbon and green methanol by moso bamboo carrying biomass solid waste

Abstract

The invention discloses a method and a system for synergistically producing hard carbon and green methanol by moso bamboo carrying biomass solid waste. The method comprises the following steps: separating moso bamboos into bamboo green strips, bamboo flesh and bamboo joints; the bamboo green strips are sold; the bamboo meat is prepared into the high-performance sodium ion battery hard carbon negative electrode material through a full-physical method comprising high-pressure instantaneous pressure relief wall breaking, deep physical impurity removal, anaerobic pyrolysis, high-temperature high-pressure and negative-pressure modification and carbon deposition; the bamboo joints and the biomass solid waste are crushed and pyrolyzed to generate synthesis gas, and the synthesis gas and hydrogen prepared from renewable energy electrolyzed water are used for synthesizing green methanol together. The system integrates five subsystems, namely a raw material treatment subsystem, a hard carbon preparation subsystem, a hydrogen production subsystem, a green alcohol synthesis subsystem and a resource circulation subsystem, hard carbon production tail gas and organic waste residue incineration flue gas are recycled as supplementary carbon sources for green alcohol synthesis, organic bacterial manure is prepared through bamboo vinegar fermentation, wastewater is recycled, and bricks are prepared from ash residues. Differentiated high-value utilization and near-zero-emission green production of all components of the moso bamboo and the biomass solid waste are realized.

Description

Technical Field

[0001] This invention relates to the field of high-value comprehensive utilization of biomass resources and preparation of clean energy materials, specifically to a systematic method for the integrated production of hard carbon anode materials for sodium-ion batteries and green methanol by co-processing bamboo and biomass solid waste. Background Technology

[0003] Currently, the preparation of hard carbon materials mainly focuses on biomass precursors (such as coconut shells, bamboo, and straw) and synthetic polymer precursors (such as phenolic resins). Bamboo, with its wide availability and rapid growth, has been extensively studied as an ideal carbon precursor. Existing technologies typically involve complex chemical processing steps in the preparation of bamboo-based hard carbon. For example, Chinese invention patent CN119560508A discloses a "bamboo-based hard carbon sodium electrode material and its preparation method," which involves deashing and impurity removal through vacuum impregnation with dilute acid solution and solvothermal acidolysis, followed by pre-carbonization, discharge plasma sintering, and chemical vapor deposition. While this method attempts to address the issues of deashing and structural control, its core impurity removal process heavily relies on chemical reagents such as hydrochloric acid and sulfuric acid, inevitably generating large amounts of acidic and alkaline wastewater, resulting in severe environmental pressure and high post-treatment costs. Furthermore, the process is lengthy, energy-intensive, and the residue of chemical reagents may affect the electrochemical stability of the material. Another mainstream technology is to use phenolic resin or imported coconut shells, along with strong chemical activators such as KOH and ZnCl2, to prepare hard carbon. This method not only has high raw material costs (e.g., coconut shells need to be imported), but also generates polluting waste liquid during the chemical activation process. Environmental treatment costs can account for 15%-20% of the production cost. At the same time, chemical residues can easily lead to low initial coulombic efficiency (often below 85%) and insufficient cycle life of the product.

[0004] On the other hand, green methanol, recognized as a "liquid sunshine" energy carrier, is an important direction for realizing carbon cycling and hydrogen storage. Its ideal synthesis route involves using "green hydrogen" produced by electrolyzing water using renewable energy, and then catalytically synthesizing it with captured carbon dioxide. However, this route faces challenges such as high carbon dioxide source costs, high capture energy consumption, and complex hydrogen-to-carbon ratio adjustments. Utilizing syngas (containing CO, CO2, and H2) generated from biomass pyrolysis gasification and supplemented with green hydrogen to synthesize green methanol is a promising alternative route. However, the syngas produced by traditional biomass gasification has a complex composition, many impurities, and high purification costs, and the system's energy efficiency and economic benefits need improvement.

[0005] Furthermore, agricultural production generates a large amount of biomass solid waste, such as straw and discarded mushroom substrate. Currently, most of this waste is simply incinerated or landfilled, resulting not only in resource waste but also environmental pollution. How to achieve high-value and comprehensive utilization of this type of waste is a common challenge facing the industry.

[0006] In summary, the existing technology has the following prominent problems: 1) Green and low-cost preparation processes for high-performance hard carbon materials have not yet been mastered. Chemical methods cause heavy pollution, while physical methods are incomplete in removing impurities and difficult to control the structure. 2) The synthesis of green methanol faces challenges such as high carbon source costs and low system integration. 3) There is a lack of systematic graded, classified, and high-value utilization plans for bamboo and various types of biomass solid waste, resulting in low resource utilization rate; 4) The various production processes are independent of each other and have failed to form a closed loop for the recycling of materials and energy. Overall energy and material consumption is high, and environmental friendliness is insufficient.

[0007] Therefore, developing an integrated method and system that can synergistically convert all components of moso bamboo with biomass solid waste to simultaneously produce high-performance hard carbon materials and green methanol, and achieve near-zero emissions throughout the entire process, is of vital importance for promoting the green and sustainable development of related industries. Summary of the Invention

[0008] The primary objective of this invention is to overcome the aforementioned deficiencies of the prior art and provide a method for the co-production of hard carbon and green methanol from bamboo and biomass solid waste. This method, through scientific component separation and targeted utilization of bamboo, and co-processing of biomass solid waste, constructs a green, efficient, and low-cost production chain of "raw material grading - process co-production - waste recycling."

[0009] Another objective of this invention is to provide a resource recycling system based on the above method, which realizes source reduction and resource recycling of gaseous, liquid and solid wastes in the production process, and achieves the goal of near-zero emissions in green production.

[0010] To achieve the above objectives, the present invention adopts the following technical solution: A method for co-producing hard carbon and green methanol from moso bamboo and biomass solid waste is proposed. Its core lies in the refined division of labor for moso bamboo raw materials and their co-processing with biomass solid waste. Through three main product pathways and a circular system, the resource value is maximized.

[0011] Firstly, the refined division of labor and pretreatment of raw materials.

[0012] The system provides bamboo and at least one biomass solid waste material selected from waste mushroom substrate, straw, branches, and fruit shells. The bamboo undergoes a crucial three-component separation: the bamboo strips, rich in lignocellulose and suitable for traditional bamboo products, are sold directly as a commodity; the bamboo flesh, with low ash content and uniform structure, serves as the core raw material for preparing high-performance hard carbon anode materials; and the bamboo nodes are mixed with the biomass solid waste material to serve as a carbon source for preparing green methanol. This division of labor, based on the differences in the physicochemical properties of each part of the bamboo, achieves optimal utilization of resources.

[0013] Secondly, the entire physical and refined preparation of hard carbon anode materials.

[0014] Using carefully selected bamboo pulp as the sole carbon source, an innovative, purely physical preparation process is employed, completely free of any added acids, alkalis, or other liquid chemical reagents. This method not only completely avoids chemical contamination but also achieves deep cleaning of the raw materials, precise structural design, and optimized performance through a series of unique physical recombination and reconstruction processes and precise control. The specific process steps are as follows: S2-1, High-Pressure Instantaneous Decompression and Cell Wall Breaking: Precise separation is achieved based on the compositional differences of various parts of moso bamboo. The bamboo green portion accounts for approximately 20% of the mass, but has a high ash content (>4%); the bamboo node portion accounts for approximately 5%, and also has a relatively high ash content (2%-3%); while the bamboo flesh portion has a mass fraction as high as approximately 75%, and the lowest ash content (<1.8%). This invention removes the bamboo green and bamboo nodes mechanically, specifically retaining the relatively pure bamboo flesh portion, and cuts it into bamboo flesh blocks of suitable size (e.g., approximately 2-3 cm in length). This step avoids high-ash impurities at the source, laying the raw material foundation for the preparation of low-ash hard carbon. The bamboo flesh blocks are placed in a sealed flash dehydrator, which is a high-pressure flash dehydrator disclosed in patent number CN202010341240.3, and high-pressure gas (5-10 MPa) is introduced and maintained for approximately 4-6 minutes, allowing nitrogen to fully penetrate into the cell cavities and microporous structure of the bamboo. Subsequently, the pressure is instantaneously released to atmospheric pressure within an extremely short time (controlled within 8 milliseconds). This process utilizes the extremely high pressure difference formed inside and outside the cells to generate violent volume expansion and mechanical shearing, thereby violently breaking the rigid structure of the bamboo cell walls and achieving physical "cell wall breaking." Cell wall breaking exposes intracellular contents (such as pectin and soluble ash) and promotes the physical softening of lignin, resulting in pretreated bamboo pulp blocks with a soft internal structure and exposed colloids. This method avoids the damage to the lignocellulose matrix caused by chemical or enzymatic methods, maximizing the preservation of carbon source integrity and carbonization yield.

[0015] S2-2. Fiber Bundle Preparation and Deep Impurity Removal: The pre-treated bamboo pulp blocks are fed into a hammer mill, where they are broken down into loose bamboo fiber bundles through hammering and tearing, simultaneously removing some attached impurities. The bamboo fiber bundles are then fed into a high-speed blade shearing and friction cleaning device, which is a blade-type wall-breaking machine. This device uses blades rotating at 5000-10000 rpm to generate powerful mechanical shearing force. With the assistance of water / air, the fiber bundles are further broken down, loosened, and flushed, efficiently washing away impurities such as mud and dust, achieving deep cleaning.

[0016] S2-3, Refining and Shaping: In this stage, water is used as the medium. Through a series of purely physical unit operations, the fiber bundles are opened and the specific surface area is increased to prepare clean and structurally uniform precursor particles.

[0017] Hydraulic pulping: Using strong hydraulic shearing, fiber bundles are completely broken down into single or few bundles of wood fibers to form a uniform pulp.

[0018] Pressure screening: A pressure screen with a sieve aperture of 0.1-0.2 mm is used to intercept and discharge undissociated coarse fiber bundles and solid impurities with larger particle sizes (>50μm) to obtain refined wood fiber pulp.

[0019] Filtration and Dewatering: A double-mesh filter press is used to mechanically dewater and compress the slurry under a linear pressure of 0.8-1.2 MPa. This process not only reduces the moisture content of the material to 65-70%, forming a wet wood fiber filter cake, but also uses mechanical force to tightly bind the wood fibers, initially increasing the density, and carrying away a large amount of soluble ash with the filtrate. Through the combined effect of pressure screening and filtration, the total ash content of the material can be reduced by more than 85% compared to the original bamboo pulp.

[0020] Temperature-controlled drying: A chain plate dryer is used to dry the wood fiber filter cake to a moisture content of less than 15% under hot air at 110-130℃, resulting in dry and loose wood fiber material.

[0021] Physical granulation: Dry wood fibers are fed into a ring die granulator. Without any binders, the wood fibers interweave, curl, and densify through mechanical extrusion and friction, ultimately forming cylindrical bamboo-wood fiber granules with a diameter of 5-10 mm, a length of 10-20 mm, and a bulk density of 0.45-0.55 g / cm³. These granules are characterized by uniform particle size, dense structure, and good flowability, ensuring uniform heating and consistent shrinkage during subsequent pyrolysis, which is crucial for obtaining homogeneous hard carbon precursors.

[0022] S2-4. Precursor Formation via Anaerobic Pyrolysis: Fine bamboo-wood fiber particles are placed in an anaerobic pyrolysis furnace, which is a carbonization system disclosed in patent number CN202411730517.6. The pyrolysis is performed under a programmed temperature rise protection environment with a high-purity inert gas (such as nitrogen or argon, purity ≥ 99.99%). A segmented temperature control strategy is adopted: first, the temperature is increased at 2-10℃ / min to 300-400℃ to decompose the wood fibers, then the temperature is further increased to a final temperature of 700-850℃ and held for 1-3 hours to fully carbonize the wood fibers, initially forming a disordered carbon skeleton. The volatile gases produced by pyrolysis (rich in carbon monoxide, carbon dioxide, hydrogen, etc.) are collected and transported to the condenser of the subsequent green methanol preparation system for recycling as syngas feedstock. The resulting solid is a hard carbon precursor with a carbon content > 96%.

[0023] S2-5, High Temperature, High Pressure and Negative Pressure Modification: The hard carbon precursor is transferred to the sealed cavity of the main furnace, which has both high temperature, high pressure and negative pressure control functions, and the following two steps are performed in sequence: First, a high-temperature, high-pressure densification treatment is performed: a high-pressure inert gas is introduced into the chamber to establish and maintain a static gas pressure of 2.5-3 MPa, while the temperature is raised to 800-900℃, and the treatment is carried out under these conditions for 2-3 hours. Under this high-temperature, high-pressure environment, the carbon layer walls of the hard carbon precursor soften, creep, and densify. The isotropic compressive force provided by the gas pressure effectively compacts the interlayer structure of carbon, reducing interlayer defects and excessive porosity. This process promotes the localized ordered stacking of carbon microcrystals while significantly improving the bulk density and structural rigidity of the material, laying the foundation for densification in subsequent processing.

[0024] Post-high-temperature negative pressure pore regulation treatment: Under the condition of maintaining the same temperature range (800-900℃), the furnace atmosphere is switched to a negative pressure state (absolute pressure ≤0.07MPa) and treated for 2-3 hours. During this stage, due to the synergistic effect of the sudden drop in external pressure and continuous high-temperature thermal disturbance, some micro, medium, and large pores and unstable pore structures that were not completely closed during the high-pressure stage undergo controllable collapse and shrinkage, thereby further optimizing the pore distribution, reducing ineffective pore volume, and achieving secondary densification of the carbon skeleton. The above-mentioned two-step synergistic modification mechanism of "high-pressure densification followed by negative pressure pore regulation" not only directly increases the bulk density of the material and reduces the specific surface area, but more importantly, it effectively promotes the rearrangement and ordering of the carbon layer structure, stabilizes the carbon skeleton, and optimizes the pore structure, thereby obtaining a modified precursor with higher density, more stable structure, and better performance. The heat treatment process also generates gases containing carbon monoxide, carbon dioxide, and hydrogen. These gases are also collected and combined with the pyrolysis gases from step S2-4 to form mixed gas A, which is then fed into the condenser of the subsequent green methanol preparation system.

[0025] S2-6. Crushing, Classification, and Carbon Deposition: The modified precursor is crushed, air-jet milled, and classified to obtain a fine powder. This powder is then placed in a chemical vapor deposition (CVD) apparatus under slight negative pressure (-10 to -500 Pa) and 1400-1600°C conditions, with methane (economical and stable) introduced as the carbon source gas, for 3.5-4 hours of surface deposition. This process grows a uniform, dense (approximately 5-15 nm thick) conductive carbon coating layer in situ on the surface of the hard carbon particles. This adjusts surface defects, reduces electrolyte side reactions, enhances interparticle electron conduction, and further improves the electrochemical stability and rate performance of the material.

[0026] S2-7, Compound hard carbon anode material: The surface-modified and cooled hard carbon material is scientifically graded and mixed according to the target particle size distribution. A multi-peak particle size ratio of fine, medium and coarse particles is adopted, with medium particles as the main body and fine and coarse particles in small amounts and equal proportions to obtain the finished hard carbon anode material.

[0027] To ensure high product purity and excellent batch consistency, the aforementioned high-temperature and high-pressure modification, carbon deposition, and subsequent cooling and sieving (e.g., 200-500 mesh) steps are preferably completed continuously in a cleanroom with controlled environmental parameters (temperature, humidity, cleanliness). This integrated, closed-loop production model eliminates intermediate contamination and performance fluctuations, and is a crucial guarantee for achieving stable, large-scale production of high-quality hard carbon materials.

[0028] The hard carbon anode material prepared by the above-mentioned all-physical method has the following performance indicators: ash content is less than 0.5%, proving the effectiveness of deep physical impurity removal; carbon interlayer spacing (d002) is between 0.38-0.41 nm, which is conducive to the rapid insertion and extraction of sodium ions; the specific surface area is controlled in a low range of 4-10 m² / g, which helps to improve the initial coulombic efficiency; the initial coulombic efficiency is not less than 88%, the reversible specific capacity is not less than 280 mAh / g, and the capacity retention rate is not less than 90% after 500 cycles at 1C rate, showing excellent comprehensive electrochemical performance.

[0029] Thirdly, the preparation and system of green methanol.

[0030] This approach aims to convert bamboo joints, biomass solid waste, and carbon-containing gases and hydrogen recovered throughout the system into high-value-added green methanol. The process integrates key technologies such as biomass pyrolysis gasification, deep gas purification, renewable energy hydrogen production (green hydrogen), and catalytic synthesis, forming a close material and energy coupling with the hard carbon production system. It is a core link in achieving full-scale and low-carbon utilization of resources. The specific steps are as follows: S3-1, Syngas Preparation: S3-1-1, Raw Material Processing: The separated bamboo sections are mixed with selected biomass solid waste (such as waste mushroom sticks, straw, etc.). This mixture is first pre-crushed mechanically using methods such as shredding and hammer milling, then granulated into pellets using a pellet mill, and finally dried in a fluidized bed dryer to reduce the moisture content to below 15%, resulting in uniform, dry biomass pellet raw materials. This pretreatment is beneficial for the stability and efficiency of subsequent pyrolysis.

[0031] S3-1-2, Pyrolysis and Gasification: Biomass pellets undergo pyrolysis and gasification reactions in a pyrolysis furnace at a high temperature of 700-850℃ under controlled atmosphere conditions, while a water-gas shift reaction is also coupled. This process converts solid biomass into crude syngas (mainly containing CO, H2, CO2, CH4 and a small amount of hydrocarbons), liquid products (biomass oil, bamboo vinegar), and a small amount of solid residue.

[0032] S3-1-3, Primary Separation and Recovery: The produced high-temperature gas first enters the condenser for rapid cooling. Here, condensable gas components (such as steam and tar) are condensed and separated to obtain two liquid byproducts: bamboo vinegar and biomass oil. The bamboo vinegar is directed to the fermentation and fertilizer production unit; after filtration, the clean biomass oil can be reused as a heat source fuel within the system, while the filter residue is sent to the incinerator.

[0033] S3-1-4, Heat Recovery and Dust Removal: The non-condensable gas (i.e., crude syngas, still at a relatively high temperature) exiting the condenser first enters the gas-vapor exchanger, where it exchanges heat with the medium requiring preheating within the system (such as air or raw materials entering the pyrolysis furnace), recovering waste heat and lowering its own temperature. The cooled gas then passes through a cyclone dust removal system, using centrifugal force to remove entrained fine dust particles, preventing subsequent blockage or contamination of equipment.

[0034] S3-1-5, Pressure Swing Adsorption Purification: The pre-purified gas enters the pressure swing adsorption unit. The pressure swing adsorption unit utilizes the difference in the adsorption capacity of the adsorbent for gas components under different pressures to selectively remove impurities from the crude synthesis gas. The ratio of H2, CO, and CO2 can be adjusted as needed to output refined synthesis gas that meets the hydrogen-to-carbon ratio requirements for chlorophyll synthesis.

[0035] S3-2, Hydrogen Replenishment: To achieve the ideal hydrogen-to-carbon ratio in chlorohydrin synthesis and ensure the product's "green" attributes, the system is equipped with a renewable energy-based water electrolysis hydrogen production subsystem. Clean electricity from sources such as photovoltaics and wind power drives an electrolyzer (e.g., an alkaline water electrolyzer) to decompose water and produce high-purity hydrogen ("green hydrogen"). The produced hydrogen is stored in a buffer storage tank for flexible adjustment and replenishment of the hydrogen content in the synthesis gas. S3-3, Green Alcohol Synthesis: The refined synthesis gas and supplemented green hydrogen are mixed at a stoichiometric ratio (H2-CO2) / (CO+CO2) of approximately 2.0-2.1, and then fed into the core of the green alcohol synthesis system—the methanol synthesis reactor. The reactor is filled with a copper-based catalyst (such as Cu-Zn-Al catalyst). Under a temperature of 220-280℃ and a pressure of 5-10 MPa, CO, CO2, and H2 undergo a catalytic reaction to produce methanol. The reaction product is cooled and condensed to separate crude methanol, which is then purified through distillation and other steps to finally obtain green methanol that meets fuel or chemical product standards.

[0036] Fourthly, the high-value utilization of bamboo vinegar: Bamboo vinegar is a high-value-added liquid byproduct generated during the pyrolysis of bamboo and biomass solid waste. Its main components include water, organic acids (such as acetic acid), phenols, ketones, and various trace elements. This invention abandons the traditional wastewater treatment approach, treating bamboo vinegar as a valuable organic raw material and performing targeted biotransformation to produce high-value liquid organic microbial fertilizer, thereby perfecting the resource utilization chain of liquid products and achieving "zero waste" recycling of liquid components.

[0037] In the synthesis gas purification stage of green methanol production, after the pyrolysis gas is cooled by a condenser, the bamboo vinegar is separated and collected as the lower liquid phase. The collected crude bamboo vinegar may contain a small amount of tar and suspended impurities, which need to be allowed to settle or undergo simple physical filtration to remove most of the insoluble impurities, resulting in a relatively clear raw bamboo vinegar solution.

[0038] The pretreated bamboo vinegar is pumped into a dedicated inoculation and fermentation system (such as an acid-resistant fermentation tank). Bamboo vinegar itself is highly acidic (pH approximately 2-3) and contains antibacterial components, making direct use difficult. This invention introduces specific acid-resistant, thermophilic functional bacteria (such as actinomycetes and volcanic bacteria) to construct a highly efficient composite microbial community.

[0039] In the fermenter, parameters such as temperature, pH (which can be adjusted to a suitable range for the microbial strain by appropriate dilution or the addition of buffer salts), and aeration (if necessary) are precisely controlled to carry out biological fermentation for several days to several weeks. During this process, microorganisms decompose and transform the complex organic matter in the bamboo vinegar, synthesize new metabolites, and reduce its biotoxicity.

[0040] After fermentation, the fermentation liquid is filtered or centrifuged to obtain a liquid rich in active microbial cells, metabolites (such as plant hormones, amino acids, and polysaccharides), and the effective components of bamboo vinegar that have not been completely converted.

[0041] The fermentation liquid described above can be used directly as a core raw material. Based on agricultural needs, a certain amount of nitrogen, phosphorus, potassium, and trace elements can be added, and after homogenization and stabilization, it can be made into a compound liquid organic microbial fertilizer. This product combines the functions of organic matter, beneficial microorganisms, and mineral nutrients, improving soil, promoting crop growth, and enhancing stress resistance. This represents a leap from an industrial byproduct to a high-value agricultural input.

[0042] Fifth aspect: a full-process resource recycling system.

[0043] 1. During the preparation of hard carbon, the mixed gas A (containing CO, CO2, and H2) generated by anaerobic pyrolysis, high temperature and high pressure and negative pressure modification, as well as the hydrogen generated by carbon deposition, are collected and transported to the condenser front section of the methanol preparation line. After treatment, they are incorporated into the synthesis gas.

[0044] 2. All workshop cleaning wastewater generated from equipment cleaning and site flushing in the hard carbon preparation, green methanol preparation, and bamboo vinegar high-value utilization workshops is collected and pumped into a centralized sedimentation tank. After pretreatment such as physical sedimentation and flocculation, the supernatant undergoes further deep treatment such as sand filtration, activated carbon adsorption, and disinfection to meet the process water reuse standards. It is then pumped back to each workshop for rinsing, forming an internal process water cycle.

[0045] 3. After filtration and separation, the clean biomass oil is directly recycled as a high-quality liquid fuel in the water-gas shift pyrolysis furnace or the high-temperature and high-pressure main furnace and anaerobic pyrolysis furnace for hard carbon production, replacing part of the external fossil fuels; the filter residue is sent to the incinerator as a high-calorific-value material.

[0046] 4. The sludge (sludge) produced in the sedimentation tank is dewatered by pressure filtration. The filter cake with a significantly reduced moisture content is sent to the incinerator for energy disposal due to its high organic matter content.

[0047] 5. The mixed gas B, rich in CO and CO2, generated by the incinerator is sent to the condenser front section of the chlorophyll preparation line. After being treated, it is used as a supplementary carbon source and incorporated into the methanol synthesis system.

[0048] 6. The bottom ash produced by the incinerator after high-temperature incineration of various organic waste residues mainly consists of oxides such as silicon, calcium, and aluminum, which are stable inorganic substances. This ash is transported to the supporting building materials workshop and used as one of the main raw materials for the production of aerated concrete blocks, ceramsite, or roadbed materials, realizing the ultimate utilization of solid waste in a harmless and resource-based manner, and completely eliminating solid waste landfill.

[0049] The beneficial effects of this invention are: Compared with existing technologies, this invention proposes for the first time an innovative strategy for the precise separation and differentiated high-value utilization of three components of moso bamboo: bamboo green, bamboo flesh, and bamboo nodes. By directly selling the bamboo green strips (approximately 20% by mass, with a high ash content >4%) as raw materials for traditional bamboo products, using the bamboo flesh (approximately 75% by mass, with the lowest ash content <1.8%) specifically for the preparation of high-performance hard carbon, and using the bamboo nodes (approximately 5%) in conjunction with various biomass solid wastes (such as mushroom substrate and straw) as a carbon source for chlorophyll synthesis, this method achieves complete utilization of a single moso bamboo raw material. This approach not only provides high-purity, low-cost, high-quality hard carbon precursors from the source but also completely utilizes agricultural waste resources. The overall raw material cost is significantly lower than the traditional route that relies on imported coconut shells or phenolic resins, resulting in outstanding economic benefits.

[0050] This invention completely eliminates the use of acids, alkalis, and chemical activators in the preparation of hard carbon, pioneering a new all-physical process. Through "high-pressure instantaneous pressure relief and cell wall disruption" combined with "high-speed flying knife cutting and washing" and multi-stage physical refining, deep impurity removal is achieved (ash removal rate >85%, finished product ash content <0.5%), with no chemical wastewater generated. The unique "high-temperature, high-pressure, and negative-pressure modification" technology, through the synergistic physical action of heat and pressure, precisely controls the carbon interlayer spacing (d002) within the ideal range of 0.38-0.41 nm, and stabilizes the specific surface area at a low level of 4-10 m² / g. Combined with carbon deposition coating using methane or acetylene, the resulting hard carbon material exhibits an initial coulombic efficiency of no less than 88%, a reversible specific capacity of no less than 280 mAh / g, and a capacity retention rate of no less than 90% after 500 cycles. While achieving absolutely green manufacturing, it also achieves comprehensive electrochemical performance surpassing that of products obtained through traditional chemical methods.

[0051] This invention constructs a stable syngas supply system primarily based on biomass pyrolysis gas and supplemented by multi-source waste gas recovery. It innovatively recovers all pyrolysis gas from bamboo joints and solid waste, including the modified tail gas (mixed gas A) from hard carbon production, and the flue gas from the incineration of organic waste residue throughout the system (mixed gas B). After purification, these gases are used as supplementary carbon sources in the methanol synthesis system. This design significantly broadens the carbon source sources for methanol synthesis, turning endogenous carbon-containing gases from the production process into valuable resources. It achieves efficient carbon recycling within the system, substantially reducing dependence on and costs associated with external carbon sources (such as CO2 capture), while also significantly reducing direct greenhouse gas emissions, resulting in significant environmental benefits.

[0052] This invention transcends single-product production, constructing a comprehensive resource recycling system covering gaseous, liquid, and solid waste. In terms of gas, a "syngas central circulation network" centered on chlorophyll synthesis is formed; in terms of liquid, all process wastewater is treated and reused, and bamboo vinegar is converted into high-value liquid organic fertilizer; in terms of solid, the final inorganic residue is entirely used to produce aerated concrete blocks and other building materials. Through a precise pipeline network and process design, the entire system utilizes byproducts and waste generated by each unit as raw materials or energy sources, forming a closed loop of "resource-product-recycled resource." Materials and energy are cascaded and recycled, achieving near-zero emissions of pollutants during the production process. This is a model practice of the circular economy concept in the field of biomass refining.

[0053] This method highly integrates multiple production units, including hard carbon preparation, green alcohol synthesis, bamboo vinegar liquid organic fertilizer production, and waste treatment. Through process coupling and optimization, a compact and efficient production system is formed. Core process steps (such as hard carbon modification and deposition) are completed continuously in a cleanroom, ensuring product consistency and stability. Key raw materials (methane / acetylene) and energy (green hydrogen) are closely integrated with infrastructure and renewable energy sources, further reducing operating costs and effectively minimizing the carbon footprint. This integrated system design is highly modular, easily scaled up and replicated, providing a complete and highly competitive technical solution for the large-scale, low-cost, and green production of high-performance hard carbon materials and green methanol, with broad industrialization prospects.

[0054] This invention solves multiple industry challenges simultaneously, including the green and low-cost preparation of high-performance hard carbon materials, the high-value utilization of biomass solid waste, and the economical synthesis of green methanol, through innovative division of labor in raw materials, breakthroughs in green processes, and system integration and recycling. It has outstanding advantages in terms of economic, environmental, and social benefits and is of great significance to promoting the development of the sodium-ion battery industry and the green and clean fuel industry. Attached Figure Description

[0055] Figure 1 This is a system flowchart of the present invention. Detailed Implementation

[0056] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0057] The following is for reference Figure 1 The present invention will be described as follows: Example 1: Refined Division of Labor and Pretreatment of Raw Materials This embodiment specifically illustrates the method for component separation and division of labor of bamboo raw materials: (1) Take 50 four-year-old moso bamboos of similar size, with a total weight of about 1000 kg.

[0058] (2) Fix the bamboo on the CNC slitting machine, set the program to cut it longitudinally and in layers.

[0059] (3) Peel off the hard, bright green outer layer of bamboo strips. Collect about 200 kg of bamboo strips. The wood fibers in this part are tough and can be directly packaged and sold to bamboo weaving factories.

[0060] (4) Remove the bamboo nodes inside the bamboo. Collect about 50 kg of bamboo. This part has a dense structure and high ash content, so store it separately.

[0061] (5) Obtain the main part of bamboo flesh, about 750 kg. This part is light yellow in color, uniform in texture, and has a low ash content (<1.8% according to sampling test). It is used as the core raw material for hard carbon production and is transferred to the hard carbon production workshop.

[0062] The above method achieves the physical segmentation of a single bamboo stalk, clearly separating the bamboo green, bamboo flesh, and bamboo nodes, laying the raw material foundation for subsequent differentiated utilization and making the best use of resources from the source.

[0063] S6. Precursor formation by anaerobic pyrolysis: Bamboo and wood fiber granules are placed in an anaerobic pyrolysis furnace and heated to 850℃ at a rate of 5℃ / min, and held at that temperature for 2.5 hours to obtain hard carbon precursor.

[0064] Example 2: All-physical preparation of hard carbon anode material This embodiment demonstrates in detail the physical process for preparing high-performance hard carbon from bamboo pulp.

[0065] S2-1 High-Pressure Instantaneous Decompression Cell Wall Breaking: Bamboo pulp is cut into 3cm pieces and placed into the flash-breaking device. Nitrogen gas is introduced to 7.0MPa, held for 5 minutes, and then instantaneously depressurized within 8 milliseconds. After processing, the bamboo pulp pieces expand in volume and become porous.

[0066] S2-2 Deep Impurity Removal: After the material is broken down, it is separated by a hammer mill and then enters a blade-type blender for 20 minutes of water and steam cleaning before turbid wastewater is discharged.

[0067] 2-3 Refining and Molding: After cleaning, the wood fibers are successively subjected to hydraulic pulping, sieved through a 0.20mm pressure screen, dewatered by a double-mesh filter press (pressure 1.0MPa), dried by a chain plate dryer (120℃), and shaped by a ring die granulator to obtain cylindrical fine granules with a diameter of about 10mm and a length of about 20mm.

[0068] 2-4 Anaerobic pyrolysis: The fine particles were heated to 800℃ at a rate of 5℃ / min under nitrogen protection and held at that temperature for 2 hours. The pyrolysis volatiles gas (labeled G1) was collected to obtain the hard carbon precursor.

[0069] S2-5 High Temperature and High Pressure and Negative Pressure Modification: First, high temperature and high pressure densification treatment: transfer the hard carbon precursor into the high temperature and high pressure main furnace, fill it with inert gas to establish a static gas pressure of 3MPa, raise the temperature to 900℃, and heat treat it for 3 hours under these conditions. Post-high temperature negative pressure pore control treatment: Under the condition of maintaining the same temperature, the atmosphere in the furnace is switched to a negative pressure state (absolute pressure ≤ 0.07MPa) and treated for 3 hours to obtain columnar modified precursor.

[0070] S2-6 carbon deposition: The modified body was pulverized and classified to obtain powder with a particle size of approximately 20 μm. In the carbon deposition equipment, acetylene was deposited for 4 hours at 700℃ and under slight negative pressure (-100 Pa), and the deposited byproduct hydrogen gas (labeled as H1) was collected.

[0071] S2-7 Composite Hard Carbon Anode Material: The surface-modified and cooled hard carbon material is scientifically graded and mixed according to the target particle size distribution. A multi-peak particle size ratio of fine, medium and coarse particles is adopted, with medium particles as the main body and fine and coarse particles in small amounts and equal proportions to obtain the finished hard carbon anode material BHC-Ex01.

[0072] The BHC-Ex01 was tested and the results showed: ash content 0.24%, d002 value 0.39 nm, specific surface area 8.5 m² / g, initial coulombic efficiency 90.8%, reversible specific capacity 285 mAh / g, and capacity retention of 93.0% after 500 cycles at 1C. This demonstrates that the all-physical process successfully prepared high-performance hard carbon.

[0073] Example 3: Preparation and System Integration of Green Methanol This embodiment illustrates the preparation of green methanol using bamboo joints and discarded mushroom sticks as raw materials, and integrates gas purification and green hydrogen replenishment.

[0074] S3-1, Syngas Preparation: S3-1-1, Raw material processing: The bamboo joints obtained in Example 1 are mixed with waste mushroom sticks (dry basis) at a mass ratio of 1:5. The mixture is first initially crushed by mechanical means such as shredding and hammering, then formed into granules by a granulator, and then the moisture content is reduced to below 15% by a fluidized bed dryer to obtain uniform and dry biomass pellet raw materials.

[0075] S3-1-2, Pyrolysis and Gasification: Biomass pellets undergo pyrolysis and gasification reactions in a pyrolysis furnace at a high temperature of 700-850℃ under controlled atmosphere conditions, while a water-gas shift reaction is also coupled. This process converts solid biomass into crude syngas (mainly containing CO, H2, CO2, CH4 and a small amount of hydrocarbons), liquid products (biomass oil, bamboo vinegar), and a small amount of solid residue.

[0076] S3-1-3, Primary Separation and Recovery: The produced high-temperature gas first enters the condenser for rapid cooling. Here, condensable gas components (such as steam and tar) are condensed and separated to obtain two liquid byproducts: bamboo vinegar and biomass oil. The bamboo vinegar is directed to the fermentation unit for producing liquid organic fertilizer; after filtration, the clean biomass oil can be reused as a heat source fuel within the system, while the filter residue is sent to the incinerator.

[0077] S3-1-4, Heat Recovery and Dust Removal: The non-condensable gas (i.e., crude syngas, still at a relatively high temperature) exiting the condenser first enters the gas-vapor exchanger (cooled to approximately 80°C), where it exchanges heat with the preheated medium in the system (such as air or raw materials entering the pyrolysis furnace) to recover waste heat and lower its own temperature. The cooled gas then passes through a cyclone dust removal system, using centrifugal force to remove entrained fine dust particles, preventing subsequent blockage or contamination of equipment.

[0078] S3-1-5, Pressure Swing Adsorption Purification: The gas, after preliminary purification, enters the pressure swing adsorption unit. The pressure swing adsorption unit utilizes the difference in the adsorption capacity of the adsorbent for gas components under different pressures to selectively remove impurities from the crude synthesis gas. The ratio of H2, CO, and CO2 can be adjusted as needed to output refined synthesis gas that meets the hydrogen-to-carbon ratio requirements for methanol synthesis.

[0079] S3-2, Hydrogen Replenishment: To achieve the ideal hydrogen-to-carbon ratio in methanol synthesis and ensure the "green" attributes of the product, the system is equipped with a renewable energy-based water electrolysis hydrogen production subsystem. Clean electricity from sources such as photovoltaics and wind power drives an electrolyzer (e.g., an alkaline water electrolyzer) to decompose water and produce high-purity hydrogen ("green hydrogen"). The produced hydrogen is stored in a buffer storage tank for flexible adjustment and replenishment of the hydrogen content in the synthesis gas. S3-3, Green Alcohol Synthesis: The refined synthesis gas and supplemented green hydrogen are mixed at a stoichiometric ratio (H2-CO2) / (CO+CO2) of approximately 2.0-2.1, and then fed into the core of the green alcohol synthesis system—the methanol synthesis reactor. The reactor is filled with a copper-based catalyst (such as Cu-Zn-Al catalyst). Under a temperature of 220-280℃ and a pressure of 5-10 MPa, CO, CO2, and H2 undergo a catalytic reaction to produce green alcohol. The reaction product is cooled and condensed to separate crude methanol, which is then purified through distillation and other steps to finally obtain green methanol that meets fuel or chemical product standards.

[0080] The solid waste was successfully converted into green methanol that meets the standards. The production process integrates heat recovery, deep gas purification and green hydrogen coupling. The product was tested and found to have a bio-based carbon content of over 95%.

[0081] Example 4: High-value utilization of bamboo vinegar This embodiment specifically illustrates the preparation of liquid organic microbial fertilizer by fermenting bamboo vinegar.

[0082] (1) Let the coarse bamboo vinegar solution stand for 48 hours, and take the middle layer of clear liquid. (2) Pump the clear liquid into a 5m³ fiberglass fermenter. Inoculate with a compound functional microbial agent (containing actinomycetes, volcano bacteria, etc.) at a rate of 5%. Control the fermentation temperature at 60±2℃, stir intermittently, and aerate slightly for 5 days.

[0083] (3) After fermentation, filter to obtain a yellowish-brown fermentation liquid. Add nitrogen, phosphorus, potassium and trace elements to it to make a compound liquid organic fertilizer with an N-P2O5-K2O content of 8-5-7.

[0084] By transforming acidic and biotoxic bamboo vinegar waste into agricultural fertilizer rich in organic matter, beneficial microorganisms, and mineral nutrients, the high-value utilization of liquid-phase byproducts is realized, turning waste into treasure.

[0085] Example 5: Full-process resource recycling system This embodiment demonstrates how to achieve closed-loop recycling of the byproducts and waste generated in the aforementioned embodiments.

[0086] (1) Mixed gas A and hydrogen H1 from Example 2; flue gas (mixed gas B, mainly containing CO2) from the incinerator of this example is transported through a pipeline to the main pipeline before the condenser of the methanol preparation system in Example 3, and mixed with biomass pyrolysis gas to be cooled, purified and synthesized together.

[0087] By recapturing the carbon and hydrogen resources in the waste gas from hard carbon production and incineration tail gas, and using them as supplementary raw materials for methanol synthesis, a system-wide internal circulation of carbon elements is achieved.

[0088] (2) The biomass oil separated in Example 3 is filtered, and the clean biomass oil is reused as fuel for ignition and stable combustion in the pyrolysis furnace. The wastewater from the equipment cleaning in the workshops of Examples 2, 3 and 4 is integrated and piped into the central sedimentation tank. The circulating water treated by "flocculation sedimentation + sand filtration + activated carbon + disinfection" is reused in the cleaning process of each workshop.

[0089] (3) Collect biomass oil filter residue, sedimentation tank sludge, etc., and send them to the incinerator for complete incineration at >950℃. The ash residue discharged from the incinerator is transported to the building materials workshop and used as raw material at a ratio of 15% to produce qualified aerated bricks.

[0090] Through the above-mentioned circular design, this embodiment achieves a process water reuse rate of >70% within the production system, 100% energy / resource-based disposal of organic solid waste, and the recycling of most of the carbon-containing gases generated during the production process, thus constructing a green production model that approaches "zero emissions".

[0091] The five embodiments described above together constitute a complete, continuous, and implementable solution. They specifically demonstrate the technical details and implementation effects of the invention from five dimensions: raw material division of labor, preparation of core products (hard carbon, phytol), high-value utilization of by-products (bamboo vinegar), and recycling of waste. The close coupling of material and energy flows between the embodiments verifies that the overall concept of "cooperative production, full utilization, and recycling" of the invention is not only technologically advanced but also feasible for engineering and industrialization.

[0092] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications assumed above should also be considered within the scope of protection of the present invention.

Claims

1. A method for co-producing hard carbon and green methanol from bamboo carrying biomass solid waste, characterized in that, Includes the following steps: S1. Raw material processing and division of labor: Providing raw materials such as bamboo and biomass solid waste; The bamboo is separated into bamboo green strips, bamboo flesh, and bamboo nodes; The bamboo strips are sold directly. The bamboo pulp is used to prepare hard carbon anode materials; The bamboo joints are mixed with the biomass solid waste raw materials to prepare green methanol; S2. Preparation of hard carbon anode material: Using the bamboo pulp obtained in step S1 as raw material, hard carbon anode material is prepared by physical method. S3, Green Methanol Preparation: S3-1, Syngas Preparation: The bamboo sections obtained in step S1 are mixed with biomass solid waste raw materials, crushed, granulated and dried, and then fed into a water-gas shift pyrolysis furnace for pyrolysis. The generated gas is cooled by a condenser and separated into bamboo vinegar and biomass oil. The non-condensable gas is separated into syngas containing carbon monoxide, carbon dioxide and hydrogen by a pressure swing adsorption device. S3-2, Hydrogen Replenishment: Provides a hydrogen production system for water electrolysis powered by renewable energy, with the produced hydrogen stored in hydrogen tanks; S3-3, Green alcohol synthesis: The synthesis gas obtained in step S3-1 and the hydrogen gas supplemented in step S3-2 are introduced into the green alcohol synthesis system together, and green methanol is produced under the action of a catalyst.

2. The method for co-producing hard carbon and green methanol from bamboo and biomass solid waste according to claim 1, characterized in that: Step S2 describes the physical method for preparing hard carbon anode materials, which specifically includes: S2-1, High-pressure instantaneous pressure relief and cell wall breaking: After cutting the bamboo pulp obtained in step S1 into bamboo pulp blocks, place them in an environment filled with 5-10MPa high-pressure gas, maintain the pressure, and then release the pressure instantaneously within 8 milliseconds to obtain pre-treated bamboo pulp blocks. S2-2, Preparation of fiber bundles and deep impurity removal: The pretreated bamboo pulp blocks are processed into bamboo fiber bundles by a hammer mill, and then cleaned by high-speed flying knife cutting and water / air combined cleaning. S2-3, Refining and Shaping: The cleaned material is sequentially subjected to hydraulic pulping, pressure screening, pressure filtration and dewatering, drying and granulation to obtain fine bamboo and wood fiber granules; S2-4. Precursor formation by anaerobic pyrolysis: Bamboo and wood fiber particles are pyrolyzed in an anaerobic pyrolysis furnace at 700-850℃ to obtain hard carbon precursor. S2-5. High temperature and high pressure and negative pressure modification: The hard carbon precursor is placed in a high temperature and high pressure main furnace and subjected to high temperature and high pressure densification treatment and high temperature and negative pressure porosity control treatment in sequence to obtain the modified precursor. S2-6, Crushing, Grading and Carbon Deposition: After the modified precursor is crushed, pulverized and graded, surface carbon deposition is carried out for 3.5-4 hours in a chemical vapor deposition equipment under high temperature and slight negative pressure conditions by introducing carbon source gas. S2-7, composite hard carbon anode material; Steps S2-5, S2-6, and S2-7 are completed consecutively in a cleanroom.

3. The method for co-producing hard carbon and green methanol from bamboo and biomass solid waste according to claim 1, characterized in that: The biomass solid waste raw material is at least one of the following: waste mushroom sticks, straw, branches, or fruit shells.

4. The method for co-producing hard carbon and green methanol from bamboo and biomass solid waste according to claim 1, characterized in that: The bamboo vinegar liquid separated by condensation in step S3-1 is transported to the fermentation system, where bacteria are added for fermentation, and the fermentation product is used as the raw material for compound liquid organic bacterial fertilizer.

5. The method for co-producing hard carbon and green methanol from bamboo and biomass solid waste according to claim 2, characterized in that: The biomass oil separated by condensation in step S3-1, after filtration, is used as heating fuel for pyrolysis and / or modification equipment in the water-gas shift pyrolysis furnace and / or hard carbon production process.

6. The method for co-producing hard carbon and green methanol from bamboo and biomass solid waste according to claim 2, characterized in that: It also includes recycling steps: The mixed gas A of carbon monoxide, carbon dioxide and hydrogen produced in step S2-4 anaerobic pyrolysis and step S2-5 high temperature, high pressure and negative pressure modification, as well as the hydrogen produced in step S2-6 carbon deposition, are collected and transported to the condenser, and after processing, enter the chlorophyll synthesis system.

7. The method for co-producing hard carbon and green methanol from bamboo and biomass solid waste according to claim 1, characterized in that: It also includes the following recycling steps: The cleaning wastewater generated from the hard carbon anode material preparation workshop, the green methanol preparation workshop, and the organic microbial fertilizer preparation workshop is centrally fed into a sedimentation tank for treatment. The sediment produced by precipitation is sent to an incinerator for incineration; The supernatant after treatment in the sedimentation tank is purified and reused for cleaning in each workshop. The solid waste produced by the incinerator is used to make aerated concrete blocks.

8. The method for co-producing hard carbon and green methanol from bamboo and biomass solid waste according to claim 7, characterized in that: The biomass oil separated by condensation in step S3-1 is filtered and then sent to an incinerator for incineration.

9. The method for co-producing hard carbon and green methanol from bamboo and biomass solid waste according to claim 8, characterized in that: The mixed gas B generated by the incinerator is collected and transported to the condenser. After separation, it is fed into the chlorophyll synthesis system as a syngas supplement source. The mixed gas B contains carbon monoxide and carbon dioxide.

10. The method for co-producing hard carbon and green methanol from bamboo and biomass solid waste according to claim 1, characterized in that: In step S3-1, the non-condensable gas first undergoes heat exchange through a gas-vapor exchanger, then passes through a cyclone dust removal system to remove particulate matter, and finally enters the pressure swing adsorption device.

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