95 results about "Biomass feedstock" patented technology

A chemical reformer system has an inlet, a digester, a series of chemical reformers, coolers and separators. The temperatures and pressures of the digester and chemical reformers may be regulated, where the pressure decreases from the first chemical reformer to the last and the temperature increases from the first chemical reformer to the last. The chemical reformer system may be utilized to convert feedstock biomass to output compounds, such as bio-oils.

The embodiment of the application discloses a nitrogen content prediction method, a program product, an equipment and a storage medium, comprising: obtaining experimental data of each biomass raw material under each hydrothermal liquefaction reaction condition, and constructing a data set according to the experimental data; performing cluster analysis on the data set based on the element composition of the raw material and the organic composition of the raw material to obtain each sub-data set corresponding to the data set; performing data enhancement on each sub-data set according to a predetermined random disturbance to obtain each enhanced sub-data set, and determining a model training data set according to each enhanced sub-data set; training a predetermined initial nitrogen migration and conversion prediction model based on the model training data set to obtain a target nitrogen migration and conversion prediction model. The application constructs a nitrogen migration and conversion prediction model suitable for small sample and high heterogeneity data conditions. The prediction accuracy and generalization ability of the target nitrogen migration and conversion prediction model are improved.

The application discloses a preparation system and method of supercapacitor carbon, and the system comprises a pyrolysis and pre-activation module, a gasification and activation module and a post-processing module; the pyrolysis and pre-activation module comprises a pyrolysis reactor; the gasification and activation module comprises a gasification furnace and an acid pickling tank; a feeding inlet of the post-processing module is communicated with a second discharging pipeline, and a discharging outlet of the post-processing module is used for discharging the supercapacitor carbon after post-processing; the post-processing module is further provided with a flue gas inlet communicated with a sandwich space. The mixture of biomass raw materials and chemical activators is conveyed to the pyrolysis reactor to generate biochar and pyrolysis gas through pyrolysis and pre-activation reaction; the biochar and the pyrolysis gas are conveyed to the gasification furnace to generate crude capacitive carbon and crude combustible gas through gasification and activation reaction; the crude capacitive carbon is subjected to acid pickling through the acid pickling tank to obtain capacitive carbon, and finally, the supercapacitor carbon is obtained through post-processing. The preparation system and method can improve the performance of the supercapacitor carbon and save resources.

The utility model relates to water heating stove technical field, and disclose a kind of automatic feeding structure's environmental protection type biomass water heating stove, including furnace body, the left side of furnace body is provided with crushing mechanism, the front of crushing mechanism is provided with discharge mechanism, the crushing mechanism includes fixed frame, the fixed frame is fixedly connected in the left side of furnace body near top, the fixed frame inner wall is fixedly connected with hopper, the hopper bottom is fixedly connected with discharge cylinder, the hopper inner wall top is fixedly connected with inclined plate. By being provided with crushing mechanism in the left side of furnace body, the inclined plate of hopper inner wall is convenient for the introduction of biomass raw material, first crushing roller and second crushing roller cooperate, under the first servo motor drive and gear engagement transmission, biomass raw material can be quickly crushed, and the raw material after crushing directly enters furnace cavity of furnace body through discharge cylinder, realizes automatic feeding, not only reduces manual operation, but also ensures that raw material is continuously and stably supplied, effectively improves the working efficiency of water heating stove.

This application proposes a method for preparing gradient-pore structured biochar for soil remediation microbial loading, relating to the field of biomass resource utilization technology. The preparation method includes: pyrolyzing biomass raw materials at high temperature and then cooling to obtain biochar embryos; dissolving surfactants in water to prepare an impregnation solution; impregnating the biochar embryos in the impregnation solution and drying to obtain a mesoporous template; dispersing starch in water, heating, and adding the mesoporous template while stirring, reacting, and then cooling, settling, and drying to obtain a macroporous template; and calcining the macroporous template under an inert atmosphere using a gradient heating process to obtain biochar with a gradient-pore structure. This application, through synergistic regulation of raw material composition, pretreatment process, and programmed pyrolysis activation process, achieves for the first time a continuous gradient distribution of pore size from the outside to the inside ("macropore → mesopore → micropore") within a single biochar particle, significantly improving its performance as a microbial carrier.

The application discloses a biomass fermentation process for preparing green methanol, which comprises the following steps: providing a biomass raw material, and fermenting to obtain biogas; obtaining rich-methane gas after crude purification of the biogas; obtaining qualified rich-methane gas after super-precision detoxification of the rich-methane gas; adding medium-pressure steam into the qualified rich-methane gas, and performing a methane steam reforming reaction to obtain a mixed gas; performing PSA treatment on the mixed gas to obtain a resolved gas and a raw material gas; and feeding the resolved gas into a normal-temperature catalytic heat exchange system, and taking the raw material gas as one of raw materials for methanol synthesis to prepare refined methanol. The application realizes full-chain coupling and efficient utilization, combines biomass fermentation, biogas purification and methane steam reforming, and adopts a CO2 circulation technology. The application realizes full-process energy integration: the waste heat in the fermentation process, the waste heat of the PSA resolved gas and the waste water of rectification are utilized to drive the methane steam reforming reaction, the system energy consumption is reduced, and the economic efficiency and sustainability of the system are further improved.

This invention discloses an oxygen-activated iron-rich biochar, its preparation method, and its application, relating to the field of materials technology. The preparation method includes the following steps: pulverized biomass raw materials are subjected to high-temperature pyrolysis under oxygen-deficient conditions, cooled, and sieved to obtain raw biochar powder. This powder is then thoroughly mixed with ferric nitrate nonahydrate, and KOH solution is added dropwise under oxygen-purifying conditions until the solution pH is neutral. After solid-liquid separation, a precipitate is obtained, which is then freeze-dried and finally sieved to obtain the oxygen-activated iron-rich biochar. This invention utilizes high-purity oxygen to optimize the iron-rich biochar, resulting in a material with a large specific surface area, small average pore size, and a high number of micropores, significantly enhancing its adsorption capacity. Furthermore, it eliminates the risk of secondary pollution, has a simple preparation process, and is suitable for large-scale industrialization. In addition, it exhibits excellent solidification and stabilization properties for heavy metals, especially for the adsorption of variable-valence metals like arsenic, far exceeding that of commercially available modified biochar.

The application discloses a returning material unit, and a double-fluidized bed reaction device applying the unit. The returning material unit is arranged between a combustion chamber and a gasification chamber in the double-fluidized bed reaction device and is used in a hydrogen production process of biomass raw materials. The returning material unit comprises a returning material chamber which is communicated with the gasification chamber or the combustion chamber through a feeding pipe. A first air distribution cavity is arranged at the lower part of the returning material chamber. A loosening chamber is arranged to receive bed material particles from the combustion chamber or the gasification chamber and to block gas. The middle and upper parts of the loosening chamber are separated from the returning material chamber through a partition plate. The bottom plate of the loosening chamber is arranged to be inclined towards the partition plate. A second air distribution cavity is arranged at the lower part of the loosening chamber. The returning material unit can reduce the possibility of gas channeling between hydrogen-rich synthesis gas and flue gas and reduce the fluidized dead zone while ensuring the hydrogen production rate. The structure design of the gasification chamber of the double-fluidized bed reaction device can make the solid particles realize local core-annular flow circulation, and the heat transfer between the bed material particles and the biomass particles is enhanced.

This invention provides a biomass pretreatment method using a steam-coupling twin-screw extruder, along with cellulose-containing biomass and its applications. The biomass pretreatment method includes the following steps: sequentially subjecting pre-softened biomass raw materials to steam treatment and twin-screw extrusion crushing to obtain biomass particles; the biomass particles are then subjected to a cooking reaction to obtain cellulose-containing biomass. This invention utilizes the synergistic effect of steaming and twin-screw extrusion crushing to overcome the mass transfer resistance of dense wood with low energy consumption, aiming to solve the problems of dense forest biomass structure, high energy consumption in traditional pretreatment methods, and difficulty in chemical penetration. This process can effectively reduce the amount of chemicals used to achieve efficient and directional separation of components, fully adapting to the needs of low-cost, continuous industrial production.

This invention relates to the field of adhesive technology, and discloses an environmentally friendly biomass-based underwater adhesive, its preparation method, and its applications. The adhesive is prepared by one-step melt copolymerization of three biomass raw materials: lipoic acid, caffeic acid, and cysteine. This system utilizes the ring-opening polymerization of lipoic acid to form a dynamic disulfide bond network providing cohesive force, the catechol groups of caffeic acid to provide various interfacial interactions with the substrate, and the thiol groups of cysteine ​​to simultaneously participate in network construction and inhibit catechol oxidation, thereby synergistically achieving high-strength and durable underwater adhesion. The adhesive achieves an underwater adhesion strength of up to 5.5 MPa on iron sheets, remains stable in various acid, alkali, and salt environments, and can be repeatedly recycled through hot melting. This invention uses entirely bio-based raw materials, employs a simple and non-toxic process, and is suitable for underwater remediation, marine engineering, and other fields.

The application provides a gas emission reduction functional agent for composting and a preparation method and application thereof, relates to the technical field of organic solid waste resource processing, and comprises pyrolysis treatment of biomass raw materials to form microporous biochar, wherein the pyrolysis treatment adopts limited oxygen pyrolysis conditions, the microporous biochar and the porous inorganic carrier form a multi-stage pore channel skeleton system, and the biomass raw materials include bamboo chips, rice husks and wood chips. The gas emission reduction functional agent for composting and the preparation method thereof are characterized in that the zeolite and bentonite are pretreated to form a porous inorganic carrier, the microporous biochar is combined with the carrier, the functional factor grading release particles are formed by compounding and coating treatment, and finally the composite integration treatment is performed, so that the gas emission reduction functional agent with a multi-stage pore channel skeleton system and a synergistic effect is successfully prepared, the efficiency of gas emission reduction in the composting process is improved, the components are ensured to be released as needed, and the emission reduction effect of the functional agent is enhanced.

The present application belongs to the technical field of biomass hard carbon, and particularly relates to a preparation method and application of a high-rate hard carbon negative electrode material. The preparation steps are as follows: biomass raw materials are pre-carbonized under a protective atmosphere to obtain a pre-carbonized product; the pre-carbonized product is added into a p-nitrophenol solution, stirred uniformly, poured into a reaction kettle containing a polytetrafluoroethylene carbonization bottle, and subjected to a hydrothermal reaction in a blast drying oven to obtain pretreated material, which is then crushed to obtain crushed material; the crushed material is subjected to high-temperature heat treatment under an inert atmosphere to obtain heat-treated material; the heat-treated material is mixed with liquid pitch, fused in a high-speed fusion machine to obtain fused material; and the fused material is subjected to surface modification under an inert atmosphere to obtain a high-rate hard carbon negative electrode material after cooling. The finished material can be applied in sodium ion batteries. The present application introduces nitrogen atoms, optimizes defects, improves the sodium ion transmission rate, and improves the rate performance.

This invention provides a biomass fuel and its preparation method, belonging to the field of waste utilization technology. This invention mixes different waste materials to prepare biomass raw materials, and simultaneously utilizes microbial strains to transform the organic flame retardants contained in the waste raw materials into new flammable agents through biochemical reactions. The prepared biomass fuel has high calorific value, low smoke and dust, and excellent combustion performance, making rational use of various waste materials, and is environmentally friendly, efficient, and energy-saving. The results of the embodiments show that the biomass fuel prepared by this invention has a calorific value of 35.6 MJ / kg, a calorific value of 4100 cal / g, a combustion efficiency of 99.1%, and low smoke and dust.

The application discloses a biomass double-moving-bed gasification hydrogen production system and method, and relates to the field of biomass hydrogen production technology. The system comprises a feeding unit for providing and continuously feeding pretreated large-size high-density biomass raw materials mixed with biochar containing alkali metal oxides and salts thereof; a microwave pyrolysis unit comprising a microwave heating cavity and a conveying screw, which is used for receiving the biomass raw materials from the feeding unit, and performing microwave pyrolysis on the biomass raw materials while the biomass raw materials are pushed and moved in the microwave heating cavity; the microwave heating cavity is provided with a washing gas channel for radial circumferential injection; a combustion gasification unit arranged at the lower part of the microwave pyrolysis unit and receiving gaseous volatile components and solid biochar from the microwave pyrolysis unit; the combustion gasification unit is provided with a throat combustion zone and a gasification zone. The application can effectively improve the biomass pyrolysis efficiency, enhance the lightness of pyrolysis products, reduce hydrogen loss caused by combustion, significantly improve the hydrogen production yield, improve the tar removal intensity of combustion gasification, and create better conditions for obtaining a final hydrogen product with higher quality.

This invention discloses a method for preparing a composite flotation reagent using biomass hydrothermal liquefaction products, comprising the following steps: Raw material preparation: providing biomass raw materials rich in lipids or proteins; Catalytic hydrothermal liquefaction: placing the biomass raw materials and a composite catalyst in a reactor, reacting at a temperature of 250-350℃ and a pressure of 4-20 MPa, wherein the water content of the biomass raw materials is 70-95%, and the composite catalyst contains alkaline components, metal oxide components, and rare earth element components; Product separation: separating the reaction products into oil and water to obtain bio-crude oil containing amphiphilic molecules; Flotation application: applying the bio-crude oil as a composite flotation reagent to mineral flotation, where the bio-crude oil simultaneously functions as a frother and a collector. This invention uses waste biomass as raw material to prepare a composite flotation reagent with both frother and collector functions, realizing the resource utilization of waste and the green upgrading of flotation reagents, and has the characteristics of wide raw material sources, excellent reagent performance, and environmental friendliness.

The present application relates to the technical field of biomass mixed coal combustion, and discloses a safety system for bamboo reed biomass mixed coal pulverization. The system is composed of a bamboo reed biomass raw material attribute detection module, a mixed coal proportion self-adaptive regulation and control module, a combustion environment multi-source sensing module, a safety risk quantitative evaluation module and a control strategy dynamic generation module, and the modules are connected through a data flow pipeline. The raw material attribute detection module collects water content fluctuation data and particle morphology characteristic sequences in real time; the mixed coal proportion regulation and control module calculates mixed coal ratio adjustment amount accordingly; the combustion environment sensing module synchronously obtains combustion chamber temperature field change trajectory and flue gas composition concentration time series data; the safety risk evaluation module integrates the above temperature, flue gas and ratio data to generate risk probability distribution; and the control strategy generation module analyzes the risk distribution and outputs an instruction sequence for driving an execution mechanism. The present application realizes whole-process safety monitoring and dynamic regulation and control from raw material characteristics to combustion state.

This invention belongs to the field of sodium-ion battery materials and discloses a method for preparing a sodium-ion battery hard carbon composite material: Biomass raw materials are mixed with a depolymerizing agent and subjected to a hydrothermal reaction to obtain biomass-based hydrothermal carbon; the biomass-based hydrothermal carbon is mixed with a lubricating agent and subjected to heat treatment to obtain biomass-based super-lubricated carbon; the biomass-based super-lubricated carbon, conductive carbon, and a dispersant are ball-milled to obtain a mixed carbon material; the mixed carbon material is mixed with a pore-filling material and subjected to heat treatment using a multi-stage heating program to obtain a hard carbon composite material precursor; the hard carbon composite material precursor is subjected to high-temperature carbonization treatment to obtain the sodium-ion battery hard carbon composite material. This invention also discloses the sodium-ion battery hard carbon composite material and a sodium-ion battery. This invention utilizes methods such as hydrothermal depolymerization and pore formation of biomass, surface super-lubrication, high-energy insertion of conductive carbon, and surface filling of composite carbon to regulate the atomic-level arrangement of precursor surfaces and the high-temperature flow shear strain capacity during the filling process. This results in reduced surface defects, increased closed-cell volume, and enhanced material conductivity, thereby significantly improving initial coulombic efficiency, specific capacity, cycle performance, and rate performance.

This disclosure proposes a method and application for constructing hierarchical porous carbon materials using low-melting-point eutectic salts in conjunction with bio-templates. The method includes selecting lignocellulosic biomass raw materials with vascular or pore structures, crushing, washing, and drying to obtain biomass powder; mixing at least two alkali metal halides in a eutectic ratio and grinding to obtain a low-melting-point eutectic salt mixture; physically mixing or liquid-phase impregnation mixing the biomass powder and the eutectic salt mixture, followed by drying to obtain a composite precursor; pyrolyzing the composite precursor in a high-temperature reactor under an inert atmosphere to obtain a reaction product; after cooling the reaction product to room temperature, washing it in deionized water to dissolve and separate the inorganic salts; evaporating and crystallizing the washing liquid to obtain a solid product; soaking the washed solid product in dilute acid, washing it with water until neutral, drying, and sieving to obtain the hierarchical porous carbon material.

The application discloses a preparation method of a sodium ion battery negative electrode material. The method mixes biomass raw materials, urea, boric acid and polyethylene glycol, forms a low eutectic fluid through a reactive melt extrusion process, and penetrates into the biomass in situ; then, oxidation foaming and cross-linking curing are carried out under a physical limiting pressure, and finally, high-temperature carbonization is carried out to obtain a hard carbon material. The application utilizes the synergistic effect of extrusion shearing and physical limiting to realize nitrogen and boron co-doping and precise control of the micro-pore structure, and the prepared negative electrode material has an expanded interlayer spacing, rich closed pore structure and high tap density. The method does not require a solvent, the process is continuous, effectively solves the problem that the volume energy density and specific capacity of the hard carbon material are difficult to be considered, and significantly improves the sodium storage capacity, rate performance and first cycle coulombic efficiency of the battery.

This utility model discloses a dustproof conveying device, relating to the field of biomass pellet processing technology. It includes a conveyor frame, with a first motor fixedly installed on the outside of the conveyor frame. Two symmetrical conveying rollers are rotatably connected inside the conveyor frame. The output end of the first motor is connected to one end of each conveying roller. A conveyor belt is fitted onto the two conveying rollers, and several sieving holes are evenly distributed on the conveyor belt. This utility model sieves the biomass raw materials through the sieving holes, and the fine particles slide along the inclined surface of the receiving hopper into the conveying pipe. A second motor is started to rotate the auger, conveying the fine particles through the discharge pipe to the discharge end. Simultaneously, the first motor is started to directly convey larger particles to the discharge end via the conveyor belt. By sieving and conveying the biomass raw materials, small particles are prevented from being exposed, thereby reducing dust generation during conveying and ensuring a clean and tidy production environment.

A slurry hydrocracking process is disclosed. The process comprises charging a catalyst, a bio-oil stream, a recycle stream, and a hydrogen stream to a slurry hydrocracking reactor. The bio-oil stream, and the recycle stream are hydrocracked in the presence of the catalyst and the hydrogen stream to produce a slurry hydrocracked effluent stream. A recycle stream is taken from the hydrocracked effluent stream. The bio-oil stream is added to the recycle stream which is charged into the slurry hydrocracking reactor.

The utility model discloses a kind of biomass supercritical water gasification hydrogen production systems, belong to biomass hydrogen production technical field, to realize low-cost hydrogen production, the biomass supercritical water gasification hydrogen production system includes raw material tank (1), feed pump (2), reaction furnace (3), cooler (4), gas-liquid separator (5), lye pool (6), waste liquid tank (7) and product tank (8), raw material tank (1), feed pump (2), reaction furnace (3), cooler (4) and gas-liquid separator (5) are sequentially connected.The biomass supercritical water gasification hydrogen production system uses discarded biomass raw material, without being subjected to complex processing technology, device is simple, compared with traditional water electrolysis hydrogen production, low investment, low cost.

The application discloses a production system and method of an epoxy chloropropane modified wet strength agent, and belongs to the technical field of biomass conversion. Corn stalks are used as biomass raw materials, components are separated through eutectic solvent pretreatment, bio-based monomers are prepared through enzymatic saccharification and directional fermentation of cellulose components, and bio-based polyester PEFF particles are obtained through melt polycondensation. Then, diethylenetriamine and bio-based adipic acid are used to prepare a polyamide polyamine prepolymer, and the polyamide polyamine prepolymer and the PEFF particles are used to prepare a PAA-co-PEFF composite prepolymer aqueous solution through ester-amide exchange reaction. Then, the composite prepolymer and pretreated epoxy chloropropane are used to perform controllable crosslinking reaction, and after thin film evaporation and deep dechlorination through a double-tower series fixed bed adsorption tower, the product is finally obtained through oxidation coupling and graft modification with tannin extract, pH adjustment, dilution and filtration.

This invention belongs to the field of carbon material preparation technology, and provides a nitrogen-doped porous carbon nanosheet, its preparation method, and its application. The preparation method of this invention involves sequentially pyrolyzing, acid washing, and drying white radish to obtain the nitrogen-doped porous carbon nanosheet; the pyrolysis temperature is 500-900℃; the pyrolysis is carried out under a protective atmosphere. This invention uses white radish as a biomass raw material, and nitrogen-doped porous carbon nanosheets can be obtained through pyrolysis and acid washing. The preparation method of this invention is simple to operate and low in cost; moreover, compared with existing technologies that add nitrogen-containing organic matter such as urea for nitrogen doping, the operation is simpler and more environmentally friendly. Data from the examples show that the nitrogen-doped porous carbon nanosheets prepared by this invention have excellent capacitance performance, ultra-high specific capacitance, and good rate performance.

The application provides an online near-infrared spectrum detection method and system for biomass raw material components, and relates to the technical field of component detection. Firstly, the particle size distribution and the near-infrared spectrum data of the biomass raw material are acquired in real time, and the two types of data are time-stamped and aligned to establish a correlation mapping. Secondly, based on the mapping data, the channel spacing of a multi-channel adjustable distance optical attenuator is dynamically adjusted to generate standardized spectrum data that eliminates particle size interference. Then, by assigning differentiated weights to the characteristic wavebands of each main component, enhanced characteristic spectrum data is constructed. Finally, a multi-output regression model is established using pre-set samples, and the contents of cellulose, hemicellulose, lignin and other components are simultaneously inverted by inputting the enhanced characteristic spectrum data into the model, thereby realizing rapid and accurate online detection of the components of the biomass raw material in the continuous conveying process.

The application discloses a preparation method of fruit wood, miscellaneous wood, coconut shell charcoal and activated carbon handicraft, and belongs to the technical field of biomass carbonization and carbon-based handicrafts. The method comprises the following steps: after various fruit woods, miscellaneous woods and coconut shells are cut and impurities are removed, the fruit woods, miscellaneous woods and coconut shells are loaded into a kiln, and gradient heating is performed under semi-anoxic conditions until the temperature reaches 1500 DEG C, and carbonization is performed for 15 days; after the kiln is closed and aging is performed for 5 days, natural cooling is performed, and charcoal powder is prepared through crushing; 200 parts of the charcoal powder, 20 parts of starch and 180 milliliters of water are prepared into molding slurry, and the molding slurry is poured into a mold or is engraved into a shape, and the handicraft is prepared through natural air drying; or activated carbon with an iodine adsorption value of greater than or equal to 800 mg / g is directly used, and the activated carbon is directly prepared into slurry through batching without carbonization. The method is stable and controllable, the blank body is not cracked, has high strength and a smooth appearance, can be finely engraved and can be mass-produced, and high-value-added utilization of biomass raw materials is realized.

The utility model discloses a kind of biomass particle processing is prevented jamming pellet press, belong to biomass particle processing technical field, its technical scheme main point includes pellet press body, the pellet press body includes base, driving part, pellet chamber, feed hopper and discharging shell, the inner chamber of the feed hopper is provided with auxiliary feeding assembly, the top of the discharging shell is provided with auxiliary drying assembly, it solves the pellet press of existing biomass particle processing usually lacks auxiliary feeding stirring structure, when biomass raw material enters feed hopper, raw material is easy to accumulate and jam at the junction of feed hopper and pellet chamber, so that raw material is difficult to smoothly enter pellet chamber and carry out pelletizing operation, and part of biomass raw material with greater humidity is easy to adhere to feed hopper inner wall, further aggravate feeding difficulty, and existing pellet press lacks auxiliary drying structure in discharging link, after biomass particle pelletizing forming, if particle humidity is greater, it is difficult to maintain stable shape.

The application relates to the technical field of sodium ion battery negative electrode materials, in particular to a cotton stalk-based hard carbon negative electrode material with high initial coulomb efficiency and high specific capacity and a preparation method thereof, which is regulated by carbon dioxide etching. The method comprises the following steps: pre-carbonizing cotton stalk-based biomass raw materials; crushing and grading the pre-carbonized products; washing and purifying the pre-carbonized products by using a mixed acid system; etching the purified materials in a rotary kiln under a carbon dioxide atmosphere to construct pore structures and defect structures that are beneficial to subsequent closed pore rearrangement; taking out the etched materials and performing high-temperature closed pore treatment on the etched materials in a box furnace; and performing chemical vapor deposition surface carbon coating on the etched materials in a rotary kiln or an equivalent reactor to obtain the cotton stalk-based hard carbon negative electrode material. The carbon dioxide etching temperature is preferably 600-1200 DEG C, more preferably 700-1100 DEG C, and the theoretical etching amount is 10%-50% of the mass of the obtained purified intermediate by controlling the carbon dioxide input amount. The synergistic process of the application, i.e. pre-carbonization-crushing-acid washing-carbon dioxide etching-high-temperature closed pore treatment-CVD carbon coating, can take into account the pore structure regulation, surface side reaction inhibition and interface stability improvement of the material, thereby improving the initial coulomb efficiency, reversible capacity and cycle stability of the hard carbon negative electrode material, and the application is suitable for sodium ion battery negative electrodes.

The present invention provides a high-density polyurethane foam with excellent physical properties using biomass raw materials. The present invention provides a polyurethane foam containing a biomass-derived polyol as a polyol component, having a density of 120 kg / m³ or higher and an isocyanate index of 92 or lower. The present invention also provides a polyurethane foam containing a biomass-derived polyol as a polyol component, having a density of 120 kg / m³ or higher and an elongation of 200% or higher as measured in accordance with JIS K6401:2011.