Preparation method and application of biomass-based hard foamy carbon

Abstract

The invention discloses a preparation method and application of biomass-based hard foamy carbon. The preparation method comprises the following steps: (1) pretreating a biomass raw material to prepare biochar; (2) mixing the biochar or biomass raw material with an adhesive, grinding and pressing to obtain a precursor composition; and (3) transferring the precursor composition to a heating chamber, then introducing inert gas, controlling the pressure, and carrying out gradient heating and cooling to obtain the hard foamy carbon. The hard foamy carbon disclosed by the invention can be widely applied to a plurality of fields, such as heat insulation, sound insulation and load-bearing materials in buildings. The composite material can also be used as a carrier for adsorbing heavy metal pollution in soil, and can also be used as a carrier for treating water pollution. And a filter element material used as the water purifier.

Description

Technical Field

[0001] This invention relates to the field of chemical materials technology, and more specifically to a method for preparing and applying biomass-based rigid foam carbon. Background Technology

[0002] Carbon, as a non-metallic element, is abundant on Earth and plays a vital role in various industries. Since 1985, research on novel carbon materials, such as carbon foam, fullerenes, carbon nanotubes, porous carbon, graphene, and carbon aerogels, has attracted widespread attention. Materials with carbon as their main component are called carbon materials, and due to their excellent high-temperature resistance, high structural strength, high electrical conductivity, and chemical stability, they are widely used in construction, energy, chemical industry, catalysis, and environmental protection. However, common carbon materials (such as graphene, graphylene, and carbon nanotubes) often have complex preparation processes, expensive raw materials, and are mostly derived from non-renewable fossil resources. These drawbacks limit their large-scale application.

[0003] With increasing global emphasis on green and low-carbon development, the development of sustainable, efficient, and environmentally friendly materials has become a crucial direction for research and industrial development across various fields. Against this backdrop, biomass resources such as rice husks, straw, wood flour, and distiller's grains, due to their wide availability, low cost, high renewability, and high carbon content, are gradually becoming ideal candidates to replace traditional fossil resources (such as coal, oil, and natural gas) as carbon materials. These biomasses can not only effectively alleviate resource shortages and environmental pollution problems but also align with the goal of carbon neutrality, thus attracting significant attention from academia and industry.

[0004] Biomass-based carbon materials, particularly biomass foam carbon, biomass carbon fiber, and biomass carbon aerogel, have gradually become a research hotspot due to their unique structural characteristics and excellent performance. These materials typically possess low density, low thermal conductivity, hierarchical porous structures, and high specific surface area, while also exhibiting excellent thermal stability and mechanical strength. Among them, foam carbon, with its naturally formed three-dimensional porous framework, achieves a balance between lightweight and high strength, making it suitable as a thermal insulation, flame retardant, sound-absorbing, and structural material. Biomass carbon fiber possesses excellent flexibility and electrical conductivity, showing great potential in flexible electronic devices and supercapacitors; while carbon aerogel, due to its ultra-high porosity and surface area, has broad application prospects in gas adsorption, wastewater treatment, and electrocatalysis.

[0005] Furthermore, the structure and function of biomass carbon materials can be diversified and customized through process control (such as pyrolysis temperature, atmosphere, and additives), further broadening their application scope in building energy-saving materials, environmental pollution control, energy storage devices (such as lithium-ion batteries and supercapacitors), and catalyst supports. Rigid foamed carbon is made from carbon-rich materials through processes such as foaming, curing, carbonization, and graphitization. Its unique three-dimensional network structure endows rigid foamed carbon with excellent properties such as low density, high strength, good sound insulation, and thermal insulation. In the future, combined with advanced processing technology and surface functional modification, biomass-based carbon materials are expected to bridge the gap between achieving a green circular economy and meeting the demand for high-performance engineering materials, promoting the high-quality development of sustainable materials science. Rigid foamed carbon is widely used in building materials, thermal insulation materials, sound insulation materials, electromagnetic shielding materials, electrode materials, adsorption materials, and catalyst supports.

[0006] Based on their different physical and chemical properties, rigid carbon foam can be divided into two categories: graphite-based and non-graphite-based. Graphite-based rigid carbon foam typically has lower thermal conductivity and higher electrical conductivity, but its mechanical strength is relatively low. Non-graphite-based carbon foam, on the other hand, possesses higher mechanical strength, making it suitable as a thermal insulator, and its production cost is significantly lower than that of graphite-based carbon foam. Therefore, this technology can improve the mechanical strength of rigid carbon foam, making it more suitable for a wide range of production and daily life applications.

[0007] Based on pore size, rigid carbon foam can be classified into three categories: micropores (<2nm), mesopores (2nm–50nm), and macropores (>50nm). Unlike traditional porous carbon materials, the pore size of rigid carbon foam can typically be adjusted within the nanometer to micrometer range. Generally, rigid carbon foam exhibits two pore structures. The first is an open-pore structure, where the pore units are composed of fibrous structures. The pore edges are fibrous. For carbon foam with an open-pore structure, the pores are interconnected, exhibiting ultra-high porosity even up to 99%. The other is a closed-pore structure, where the highly developed fibrous structure becomes a closed structure. Compared to the first type, carbon foam with this structure typically has lower porosity and higher mechanical strength.

[0008] The synthesis of foamed carbon, regardless of the precursor used, typically requires carbonization. Carbonization removes impurity atoms (such as H, S, N, and O) to form a carbon matrix structure and morphology. In polymer and biomass precursors, carbon crystallites exhibit a disordered arrangement and cannot withstand graphitization. Therefore, their mechanical strength is relatively poor, and their electrical and thermal conductivity are limited. Foamed carbon prepared from pitch has ordered carbon crystals and can withstand the ultra-high temperatures of graphitization. It possesses a graphite-like crystal structure, which naturally leads to improved mechanical strength, thermal conductivity, and high electrical conductivity.

[0009] Currently, various processes for preparing rigid foamed carbon have been developed, including carbonization of blown carbon precursors, carbon precursor template carbonization, expanded graphite compression, and graphene nanosheet assembly. Methods for preparing blown carbon precursors can be divided into two categories: one involves pyrolysis under pressure, and the other involves generating gas by adding foaming agents. Common foaming methods include foaming agent foaming, self-foaming foaming, template methods, and supercritical methods. The precursors for rigid foamed carbon mainly include biomass feedstocks, organic polymers, mesophase pitch, coal, and coal-derived materials. The preparation method of rigid foamed carbon is closely related to the selection of precursors; different raw materials require foaming processes suitable for their physicochemical properties.

[0010] Biomass resources (such as sucrose, starch, lignin, and straw) are an important source for preparing rigid foamed carbon, offering advantages such as low cost, wide availability, environmental friendliness, and renewability. Since these biomass resources are natural polymers with physicochemical properties similar to some organic polymers, they are often prepared using foaming or template methods. Summary of the Invention

[0011] In view of this, the present invention provides a method for preparing biomass-based rigid foam carbon.

[0012] The conversion from biomass to foamed carbon is a complex system involving multiple stages of reaction, including pyrolysis, foaming, and carbonization. Its basic principle can be summarized as "gas generation—structural foaming—skeleton carbonization—pore fixation." Biomass is composed of macromolecular organic components such as cellulose, hemicellulose, and lignin. During heating, it first undergoes pyrolysis, producing gases such as CO2, CO, CH4, and H2O. These gases diffuse and become trapped in the viscous organic matrix, driving the material to expand in volume and form a uniform pore structure. In this stage, the selection and ratio of binders and biomass components significantly influence the bubble formation rate, stability, and final pore size distribution. Subsequently, the system continues to heat under an inert atmosphere, and the biomass gradually enters the carbonization stage. Pyrolysis volatiles are further released, and the carbon skeleton gradually enriches and solidifies, thus fixing the porous structure formed in the foaming stage and obtaining the preliminary foamed carbon material. By precisely controlling the heating rate and holding time, skeleton collapse and pore shrinkage can be avoided, ensuring that the foamed carbon has high porosity and structural integrity. In subsequent processing, the resulting foamed carbon not only possesses the characteristics of being lightweight, having a high specific surface area, and having a multi-level porous structure, but also exhibits excellent thermal insulation, fire resistance, and environmental functionality, providing a solid material foundation for its application in building materials and environmental remediation.

[0013] To achieve the above objectives, the present invention adopts the following technical solution:

[0014] A method for preparing biomass-based rigid foam carbon includes the following steps:

[0015] (1) Biochar was prepared from biomass raw materials through pretreatment;

[0016] (2) Mix biochar or biomass raw materials with binder, and then grind and press to obtain a precursor composition;

[0017] (3) The precursor composition is transferred to the heating chamber, then an inert gas is introduced, the pressure is controlled, and the mixture is heated by gradient and cooled to obtain the rigid foam carbon.

[0018] Preferably, the biomass raw materials mentioned in step (1) include any one of corn stalks, soybean stalks, wheat stalks, rice straw, reed stalks, rice husks, pine powder, bamboo, corn cobs, walnut shell powder, biogas residue, and distiller's grains.

[0019] Preferably, the fermentation tank includes any one of corn fermentation tank, glutinous rice fermentation tank, sorghum fermentation tank, wheat fermentation tank, and barley fermentation tank.

[0020] Preferably, the pretreatment in step (1) is one of pyrolysis carbonization, hydrothermal carbonization, microwave carbonization, activation carbonization, baking carbonization, and gasification of residual carbon.

[0021] Preferably, the adhesive in step (2) is one of alkaline lignin, tannin, starch, flour, biogas slurry, and bio-oil; the adhesive accounts for 0-100% of the total weight of the mixture.

[0022] Preferably, the grinding in step (2) is performed by ball milling or pulverizing for 30-300 min until the particle size is 0.1-200 μm; the pressing pressure is 0.1-30 MPa and the pressing time is 5-180 s; the pressing includes cold pressing or hot pressing, and the hot pressing temperature is 20-100℃.

[0023] Preferably, the combustible gas in step (3) is nitrogen, argon or helium.

[0024] Preferably, the pressure in step (3) is 0-1 MPa.

[0025] Preferably, the gradient heating is as follows: first, the temperature is increased to 300-450℃ at a rate of 0.1-40℃ / min and held for 10-60min, and then heated to 450-1000℃ and held for 60-90min.

[0026] The structure of the pressing mold used in this invention, from top to bottom, consists of a cover plate, a cover block, a mold body, and a base plate;

[0027] The mold body includes four side walls arranged in a rectangular cavity structure to form a cavity for filling the precursor composition, which can accommodate the expansion of carbon foam as pores are generated in the composition during the carbon foam formation process.

[0028] The base plate is bolted to the mold body; a cover block provides pressure during heating. This pressure helps control the expansion direction and structural density of the material during foaming and carbonization, thereby obtaining rigid foamed carbon material with the desired size, shape, and physical properties. The entire mold assembly is designed to ensure structural stability and controllability during foaming and carbonization, while facilitating the removal of the rigid foamed carbon material from the mold and subsequent machining.

[0029] Another object of the present invention is to provide rigid foam carbon prepared by the above-mentioned method for use as a heat insulation, sound insulation and load-bearing material in buildings, or as a carrier for adsorbing heavy metal pollution and treating water pollution.

[0030] As can be seen from the above technical solution, compared with the prior art, the present invention has the following beneficial effects: The present invention produces foamed carbon by using biomass or biochar as a matrix under higher temperature pyrolysis, which has the characteristics of high compressive strength (45.1-87.4MPa) compared with existing foamed carbon, while its density change is not significant (0.1-0.2g / cm³). 3 Although its porosity is higher than that of traditional engineering carbon materials, it has better thermal and sound insulation properties. Therefore, it can be used as a sound and heat insulation material for buildings. Compared with traditional foamed carbon, it has higher strength, and compared with engineering carbon materials, it has a higher thermal and sound insulation coefficient while retaining the original high strength. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the pressure mold structure used in this invention.

[0033] In the diagram: 101-Cover plate; 102-Cover block; 103-Cavity; 104-Mold body; 105-Base plate; 106-Bolt.

[0034] Figure 2 The image shows the morphology and microstructure of rice straw-based foamed carbon at 400℃ in Example 20 of this invention, captured by scanning electron microscopy.

[0035] Figure 3 The image shows the morphology and microstructure of rice straw-based foamed carbon at 800℃ in Example 20 of this invention, captured by scanning electron microscopy.

[0036] Figure 4 The image shows the morphology and microstructure of rice straw-based foamed carbon at 1200℃ in Example 20 of this invention, captured by scanning electron microscopy. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] This invention discloses a method for preparing biomass-based rigid foam carbon. Rigid foam carbon is prepared using the above method. Specific steps are as follows:

[0039] Step 1: Grind the biomass and binder from the precursor composition in a ball mill or pulverizer for 10-300 minutes according to a certain ratio. This ensures that the components are mixed evenly and that the particle size of the materials reaches 0.1-200μm.

[0040] Step 2: Pour the precursor composition or biomass into... Figure 1 In the molding component 103 shown, cold pressing or hot pressing (20-100℃) is performed under a pressure of 20-50MPa for 5-180s to form a fixed precursor composition block.

[0041] Step 3: The mixture is then transferred to the heating chamber, and as follows Figure 1 The top cover 102 is placed over the chamber. Inert gas is introduced into the heating chamber at a pressure gauge reading of 0-1 MPa, and the chamber is heated to approximately 300-450°C at a heating rate of 0.1 to 40°C / min, and maintained for 10-60 minutes. This decomposes lignin and other substances within the chamber, forming gas and creating pores.

[0042] Step 4: Next, heat to 450-1000℃ and maintain for 60-90 minutes. Only a higher temperature can ensure that the strength of the foamed carbon meets the requirements. Then, cool slowly. After removing the foam from the mold, process the rigid foamed carbon sample into the required size by sawing or other machining methods.

[0043] The raw materials selected in this embodiment of the invention are as follows:

[0044] The precursor assembly consists of two components: matrix component A (0-100%) and binder B (0-100%).

[0045] Component A: The biomass matrix used includes corn stalks, soybean stalks, wheat stalks, rice husks, rice straw, pine powder, biogas residue, and biochar. For matrix processing, these raw lignins are ground into fine powder using a ball mill or pulverizer, with a particle size ranging from 1 to 200 μm, and labeled as component A1 (rice straw), A2 (soybean straw), A3 (wheat straw), A4 (corn stalks), A5 (reed straw), A6 (rice husks), A7 (pine powder), A8 (biogas residue), A9 (corn distillers' grains), A10 (glutinous rice distillers' grains), A11 (sorghum distillers' grains), A12 (wheat distillers' grains), A13 (barley distillers' grains), A14 (bamboo), A15 (corn cob), and A16 (walnut shell powder). The biomass is dried after being ground into fine powder using a ball mill or pulverizer.

[0046] Component B: As a binder for biomass matrix or directly as a rigid foam carbon matrix, B1 (alkaline lignin), B2 (tannin), B3 (starch), B4 (flour), B5 (bio-oil), and B6 (biogas slurry) are added to the precursor as a binder or rigid foam carbon matrix.

[0047] Component C: The biochar matrix used includes biochar obtained from biomass such as corn stalks, soybean stalks, wheat stalks, rice husks, rice straw, pine powder, and biogas residue through the most suitable pyrolysis method. For matrix processing, these raw lignins are ground into fine powder using a ball mill or pulverizer, with a particle size ranging from 1 to 200 μm, and labeled as components C1 (rice straw biochar), C2 (soybean straw biochar), C3 (wheat straw biochar), C4 (corn straw biochar), C5 (reed straw biochar), C6 (rice husk biochar), C7 (pine wood powder biochar), C8 (biogas residue biochar), C9 (corn distillers' grains biochar), C10 (glutinous rice distillers' grains biochar), C11 (sorghum distillers' grains biochar), C12 (wheat distillers' grains biochar), C13 (barley distillers' grains biochar), C14 (bamboo biochar), C15 (corn cob biochar), and C16 (walnut shell biochar), etc. After being ground into fine powder using a ball mill or pulverizer, they are dried.

[0048] The characterization method in this embodiment is as follows:

[0049] The morphology and microstructure of rigid foamed carbon samples were studied using electron microscopy.

[0050] The apparent density (Da) and true density (Dt) of the rigid foam carbon samples were measured according to the standard methods ASTM D 1622 (GB / T6343-2009) and ASTM D 792-08 (GB-T 24203-2024).

[0051] The formula for calculating the bulk porosity of rigid carbon foam samples is: P(%) = 100 × ((Dt-Da) / (Dt), where P is the bulk porosity; Dt is the true density; and Da is the apparent density.

[0052] The mechanical properties of rigid carbon foam samples were determined according to ASTM standards. Compressive strength was tested according to ASTM standard C365 / C365M-05. Tests were performed at room temperature on an electronic universal testing machine.

[0053] Thermal conductivity was measured at room temperature using a laser flash thermal analyzer according to ASTM standard E1225.

[0054] The fire resistance test utilizes GB / T 10294-2008 to measure the thermal resistance of insulation materials. The experimental platform is a double-specimen device, consisting of two nearly identical specimens sandwiching a heating unit. The heating unit comprises a circular or square central heater and two metal panels. Heat flow is transferred from the heating unit to the cooling units on both sides of the specimen. The thermal resistance R can be calculated from the heat flux density q and the temperature difference T, using the formula: R(m 2 ·W / K)=T / q, and using the formula: λ=R / L, we obtain the thermal resistivity: λ(m·K) / W.

[0055] The sound insulation coefficient was modified to measure the decrease in sound intensity before and after the object was moved to a 1000 Hz sound frequency. Specific surface area was measured using an FBT9 specific surface area meter.

[0056] The specific implementation examples are as follows:

[0057] Example 1

[0058] This study investigated the performance characteristics of foamed carbon produced under cold pressing using different proportions of biochar and binder. Component C1 (rice straw biochar) and binder B1 (alkaline lignin) were mixed according to the proportions shown in Table 1, with a total weight of 15g. The components were added one by one into a ball mill or pulverizer and ground for 10 minutes. The mixture was then poured into… Figure 1 In the molding assembly 103 chamber shown, cold pressing is performed at a pressure of 5 MPa for 30 seconds. The mixture is then transferred to the heating chamber and... Figure 1The top cover 102 was placed over the chamber. Nitrogen gas was introduced into the heating chamber, with a pressure gauge reading of 0.5 MPa. The chamber was heated to approximately 300°C at a heating rate of 30°C / min and held for 20 min. Subsequently, the temperature was increased to 1450°C at a heating rate of 20°C / min and held for 60 min. The chamber was then slowly cooled. After removing the foam from the mold, the rigid carbon foam samples were processed into the desired dimensions by sawing or other machining methods. Table 1 shows the performance data of rigid carbon foam with different formulations. All materials passed the fire resistance test.

[0059] Table 1: Parameters of Rigid Foam Carbon

[0060]

[0061]

[0062] Example 2

[0063] This study investigated the performance characteristics of foamed carbon produced under hot pressing using different ratios of biomass and binder. Component C1 (rice straw biochar) and binder B1 (alkaline lignin) were mixed according to the ratios shown in Table 1, with a total weight of 15g. The components were added one by one into a ball mill or pulverizer and ground for 10 minutes. The mixture was then poured into… Figure 1 In the molding assembly 103 chamber shown, hot pressing was performed at 5 MPa pressure and 95°C for 30 seconds. The mixture was then transferred to the heating chamber and... Figure 1 The top cover 102 is placed over the chamber. Nitrogen gas is introduced into the heating chamber, with a pressure gauge reading of 0.5 MPa. The chamber is heated to approximately 300°C at a heating rate of 20°C / min and held for 20 min. Subsequently, the temperature is increased to 1200°C at a heating rate of 30°C / min and held for 60 min. The chamber is then slowly cooled. After removing the foam from the mold, the rigid foam carbon samples are processed into the desired dimensions by sawing or other mechanical methods. Table 2 shows the performance data of rigid foam carbon with different proportions. The data indicate that the apparent density and compressive strength increase with the increase of the B1 (alkaline lignin) ratio. The porosity gradually decreases. The lowest density is 0.37 g / cm³ when the entire sample is rice straw. 3 Under conditions of entirely alkaline lignin, a compressive strength of 56.1 MPa was achieved. Hot pressing of the precursor composition, compared to cold pressing, improved density and compressive strength of the rigid carbon foam.

[0064] Table 2: Parameters of Rigid Carbon Foam

[0065]

[0066] Example 3

[0067] This study investigated the performance characteristics of biomass and binders used to produce foamed carbon under hot pressing at different temperatures. Component C1 (rice straw biochar) totaling 12.75g and binder B1 (alkaline lignin) totaling 2.25g, totaling 15g, were added one by one to a ball mill or pulverizer and ground for 10 minutes. The mixture was then poured into... Figure 1 In the molded component 103 chamber shown, a hot-pressing treatment at 95°C was performed at a pressure of 5 MPa for 30 seconds. The mixture was then transferred to the heating chamber and... Figure 1 The top cover 102 is placed over the chamber. Nitrogen gas is introduced into the heating chamber, with a pressure gauge reading of 0.5 MPa. The chamber is heated to approximately 300°C at a heating rate of 20°C / min and held for 20 min. Subsequently, the temperature is increased to 400-1450°C at a heating rate of 30°C / min and held for 60 min. The chamber is then slowly cooled. After removing the foam from the mold, the rigid carbon foam sample is processed into the desired size by sawing or other machining methods. Table 3 shows the performance data of the rigid carbon foam at different final temperatures. The data indicate that the apparent density and compressive strength increase with the increase of the B1 (alkaline lignin) ratio. Porosity gradually decreases. Compared with cold pressing, hot pressing of the precursor composition can improve the density and compressive strength of the rigid carbon foam.

[0068] Table 3 Rigid Foam Carbon

[0069]

[0070] Example 4

[0071] Five precursor compositions were prepared by mixing 10.5g each of components C1-C5 (straw biochar) with 4.5g of binder B1 (alkaline lignin) to form five precursor compositions. These were then added one by one to a ball mill or pulverizer and ground for 10 minutes. The mixture was then poured into... Figure 1 In the molding assembly 103 chamber shown, cold pressing is performed at a pressure of 5 MPa for 30 seconds. The mixture is then transferred to the heating chamber and... Figure 1 The top cover 102 is placed over the chamber. Nitrogen gas is introduced into the heating chamber, with a pressure gauge reading of 0.5 MPa. The chamber is heated to approximately 300°C at a heating rate of 20°C / min and held for 20 min. Subsequently, the temperature is increased to 1200°C at a heating rate of 30°C / min and held for 60 min. The chamber is then slowly cooled. After removing the foam from the mold, the rigid carbon foam samples are processed into the desired dimensions by sawing or other machining methods. Table 4 shows the performance data of rigid carbon foam with different proportions. Table 4 also shows the theoretical data for rigid carbon foam at different temperatures, and all carbon foam samples passed the fire resistance test.

[0072] Table 4: Foam Carbon Parameters

[0073]

[0074] Example 5

[0075] Five precursor compositions were prepared by mixing 12.75g each of components C1-C5 (straw biochar) with 2.25g of binder B2 (tannin) to form five precursor compositions. These were then added one by one to a ball mill or pulverizer and ground for 10 minutes. The mixture was then poured into... Figure 1 In the molding assembly 103 chamber shown, cold pressing is performed at a pressure of 5 MPa for 30 seconds. The mixture is then transferred to the heating chamber and... Figure 1 The top cover 102 is placed over the chamber. Nitrogen gas is introduced into the heating chamber at a pressure gauge reading of 0.5 MPa, and the chamber is heated to approximately 300°C at a heating rate of 20°C / min, and held for 20 min. Subsequently, the temperature is increased to 1200°C at a heating rate of 30°C / min and held for 60 min. The chamber is then slowly cooled. After removing the foam from the mold, the rigid carbon foam samples are processed into the desired dimensions by sawing or other machining methods. Table 5 shows the performance data of rigid carbon foam with different formulations. All carbon foam samples passed the fire resistance test.

[0076] Table 5: Foam Carbon Parameters

[0077]

[0078]

[0079] Example 6

[0080] Five precursor compositions were prepared by mixing 12.75g each of components C1-C5 (straw biochar) with 2.25g of binder B3 (starch) to form five precursor compositions. These were then added one by one to a ball mill or pulverizer and ground for 10 minutes. The mixture was then poured into... Figure 1 In the molding assembly 103 chamber shown, cold pressing is performed at a pressure of 5 MPa for 30 seconds. The mixture is then transferred to the heating chamber and... Figure 1 The top cover 102 is placed over the chamber. Nitrogen gas is introduced into the heating chamber at a pressure gauge reading of 0.5 MPa, and the chamber is heated to approximately 300°C at a heating rate of 20°C / min, and held for 20 min. Subsequently, the temperature is increased to 1200°C at a heating rate of 30°C / min and held for 60 min. The chamber is then slowly cooled. After removing the foam from the mold, the rigid carbon foam samples are processed into the desired dimensions by sawing or other machining methods. Table 6 shows the performance data of rigid carbon foam with different formulations. All carbon foam samples passed the fire resistance test.

[0081] Table 6: Foam Carbon Parameters

[0082]

[0083] Example 7

[0084] Five precursor compositions were prepared by mixing 12.75g each of components C1-C5 (straw biochar) with 2.25g of binder B4 (flour). Each component was added to a ball mill or grinder and ground for 10 minutes. The mixture was then poured into... Figure 1 In the molding assembly 103 chamber shown, cold pressing is performed at a pressure of 5 MPa for 30 seconds. The mixture is then transferred to the heating chamber and... Figure 1 The top cover 102 is placed over the chamber. Helium gas is introduced into the heating chamber, with a pressure gauge reading of 0.5 MPa. The chamber is heated to approximately 300°C at a heating rate of 20°C / min and held for 20 min. Subsequently, the temperature is increased to 1200°C at a heating rate of 30°C / min and held for 60 min. The chamber is then slowly cooled. After removing the foam from the mold, the rigid carbon foam samples are processed into the desired dimensions by sawing or other machining methods. Table 7 shows the performance data of rigid carbon foam with different formulations. All carbon foam samples passed the fire resistance test.

[0085] Table 7: Foam Carbon Parameters

[0086]

[0087] Example 8

[0088] Component C6 (rice husk biochar) was mixed at 12.75g each with binders B1 (alkaline lignin) and B4 (flour) totaling 2.25g to form three different precursor compositions. These were then added one by one to a ball mill or pulverizer and ground for 10 minutes. The mixture was then poured into... Figure 1 In the molding assembly 103 chamber shown, cold pressing is performed at a pressure of 5 MPa for 30 seconds. The mixture is then transferred to the heating chamber and... Figure 1 The top cover 102 is placed over the chamber. Helium gas is introduced into the heating chamber, with a pressure gauge reading of 0.5 MPa. The chamber is heated to approximately 300°C at a heating rate of 20°C / min and held for 20 min. Subsequently, the temperature is increased to 1200°C at a heating rate of 30°C / min and held for 60 min. The chamber is then slowly cooled. After removing the foam from the mold, the rigid carbon foam samples are processed into the desired dimensions by sawing or other machining methods. Table 9 shows the performance data of rigid carbon foam with different formulations. All carbon foam samples passed the fire resistance test.

[0089] Table 8: Foam Carbon Parameters

[0090]

[0091]

[0092] Example 9

[0093] Component C7 (pine wood powder biochar) was mixed at 12.75g each with binders B1 (alkaline lignin) and B4 (flour) totaling 2.25g to form three different precursor compositions. These were then added one by one to a ball mill or pulverizer and ground for 10 minutes. The mixture was then poured into… Figure 1 In the molding assembly 103 chamber shown, cold pressing is performed at a pressure of 5 MPa for 30 seconds. The mixture is then transferred to the heating chamber and... Figure 1 The top cover 102 is placed over the chamber. Helium gas is introduced into the heating chamber, with a pressure gauge reading of 0.5 MPa. The chamber is heated to approximately 300°C at a heating rate of 20°C / min and held for 20 min. Subsequently, the temperature is increased to 1200°C at a heating rate of 30°C / min and held for 60 min. The chamber is then slowly cooled. After removing the foam from the mold, the rigid carbon foam samples are processed into the desired dimensions by sawing or other machining methods. Table 9 shows the performance data of rigid carbon foam with different formulations. All carbon foam samples passed the fire resistance test.

[0094] Table 9: Foam Carbon Parameters

[0095]

[0096] Example 10

[0097] Take 15g of component C8 (biochar residue) and mix it with 50ml of binder B5 (biogas slurry). Dry the mixture in a drying oven at 90 degrees Celsius to obtain 15g of solid mixture. Grind the mixture in a ball mill or pulverizer for 10 minutes. Pour the mixture into... Figure 1 In the molding assembly 103 chamber shown, cold pressing is performed at a pressure of 5 MPa for 30 seconds. The mixture is then transferred to the heating chamber and... Figure 1 The top cover 102 is placed over the chamber. Argon gas is introduced into the heating chamber, with a pressure gauge reading of 0.5 MPa. The chamber is heated to approximately 300°C at a heating rate of 30°C / min and held for 20 min. Subsequently, the temperature is increased to 1450°C at a heating rate of 20°C / min and held for 60 min. The mixture is then slowly cooled. After removing the foam from the mold, performance testing is performed, and its apparent density is found to be 0.99 g / cm³. 3 The porosity is 45.4% and the compressive strength is approximately 76.9 MPa.

[0098] Example 11

[0099] Five precursor compositions were prepared by mixing 12.75g each of components C9-C13 (distillers' grains biochar) with 2.25g of binder B1 (alkaline lignin). These were then added one by one to a ball mill or pulverizer and ground for 10 minutes. The mixture was then poured into... Figure 1 In the molding assembly 103 chamber shown, cold pressing is performed at a pressure of 5 MPa for 30 seconds. The mixture is then transferred to the heating chamber and... Figure 1 The top cover 102 is placed over the chamber. Helium gas is introduced into the heating chamber, with a pressure gauge reading of 0.5 MPa. The chamber is heated to approximately 300°C at a heating rate of 20°C / min and held for 20 min. Subsequently, the temperature is increased to 1200°C at a heating rate of 30°C / min and held for 60 min. The chamber is then slowly cooled. After removing the foam from the mold, the rigid carbon foam samples are processed into the desired dimensions by sawing or other machining methods. Table 10 shows the performance data of rigid carbon foam with different proportions. Table 10 also shows the theoretical data for rigid carbon foam at different temperatures, and all carbon foam samples passed the fire resistance test.

[0100] Table 10: Foam Carbon Parameters

[0101]

[0102] Example 12

[0103] Five precursor compositions were prepared by mixing 12.75g each of components C9-C13 (distillery lees biochar) with 2.25g of binder B2 (tannins) to form five precursor compositions. These were then added one by one to a ball mill or pulverizer and ground for 10 minutes. The mixture was then poured into… Figure 1 In the molding assembly 103 chamber shown, cold pressing is performed at a pressure of 5 MPa for 30 seconds. The mixture is then transferred to the heating chamber and... Figure 1 The top cover 102 is placed over the chamber. Helium gas is introduced into the heating chamber, with a pressure gauge reading of 0.5 MPa. The chamber is heated to approximately 300°C at a heating rate of 20°C / min and held for 20 min. Subsequently, the temperature is increased to 1200°C at a heating rate of 30°C / min and held for 60 min. The chamber is then slowly cooled. After removing the foam from the mold, the rigid carbon foam samples are processed into the desired dimensions by sawing or other machining methods. Table 11 shows the performance data of rigid carbon foam with different formulations. All carbon foam samples passed the fire resistance test.

[0104] Table 11: Foam Carbon Parameters

[0105]

[0106] Example 13

[0107] Five precursor compositions were prepared by mixing 12.75g each of components C9-C13 (distillers' grains biochar) with 2.25g of binder B3 (starch) to form five precursor compositions. These were then added one by one to a ball mill or pulverizer and ground for 10 minutes. The mixture was then poured into... Figure 1 In the molding assembly 103 chamber shown, cold pressing is performed at a pressure of 5 MPa for 30 seconds. The mixture is then transferred to the heating chamber and... Figure 1 The top cover 102 is placed over the chamber. Helium gas is introduced into the heating chamber, with a pressure gauge reading of 0.5 MPa. The chamber is heated to approximately 300°C at a heating rate of 20°C / min and held for 20 min. Subsequently, the temperature is increased to 1200°C at a heating rate of 30°C / min and held for 60 min. The chamber is then slowly cooled. After removing the foam from the mold, the rigid carbon foam samples are processed into the desired dimensions by sawing or other machining methods. Table 12 shows the performance data of rigid carbon foam with different formulations. All carbon foam samples passed the fire resistance test.

[0108] Table 12: Foam Carbon Parameters

[0109]

[0110]

[0111] Example 14

[0112] Five precursor compositions were prepared by mixing 12.75g each of components C9-C13 (distillers' grains biochar) with 2.25g of binder B4 (flour). These were then added one by one to a ball mill or grinder and ground for 10 minutes. The mixture was then poured into... Figure 1 In the molding assembly 103 chamber shown, cold pressing is performed at a pressure of 5 MPa for 30 seconds. The mixture is then transferred to the heating chamber and... Figure 1 The top cover 102 is placed over the chamber. Helium gas is introduced into the heating chamber at a pressure gauge reading of 0.5 MPa, and the chamber is heated to approximately 300°C at a heating rate of 20°C / min, and held for 20 min. Subsequently, the temperature is increased to 1200°C at a heating rate of 30°C / min and held for 60 min. The chamber is then slowly cooled. After removing the foam from the mold, the rigid carbon foam samples are processed into the desired dimensions by sawing or other machining methods. Table 13 shows the performance data of rigid carbon foam with different formulations. All carbon foam samples passed the fire resistance test.

[0113] Table 13: Foam Carbon Parameters

[0114]

[0115] Example 15

[0116] Four different precursor compositions were prepared by mixing 12.75g of component C14 (bamboo biochar) with 2.25g each of binders B1 (alkaline lignin) and B4 (flour). Each composition was added to a ball mill or pulverizer and ground for 10 minutes. The mixture was then poured into... Figure 1 In the molding assembly 103 chamber shown, cold pressing is performed at a pressure of 5 MPa for 30 seconds. The mixture is then transferred to the heating chamber and... Figure 1 The top cover 102 is placed over the chamber. Helium gas is introduced into the heating chamber, with a pressure gauge reading of 0.5 MPa. The chamber is heated to approximately 300°C at a heating rate of 20°C / min and held for 20 min. Subsequently, the temperature is increased to 1200°C at a heating rate of 30°C / min and held for 60 min. The chamber is then slowly cooled. After removing the foam from the mold, the rigid carbon foam samples are processed into the desired dimensions by sawing or other machining methods. Table 14 shows the performance data of rigid carbon foam with different formulations. All carbon foam samples passed the fire resistance test.

[0117] Table 14: Foam Carbon Parameters

[0118]

[0119] Example 16

[0120] Four different precursor compositions were prepared by mixing 12.75g of component C14 (corn cob biochar) with 2.25g each of binders B1 (alkaline lignin) and B4 (flour). These were then added one by one to a ball mill or grinder and ground for 10 minutes. The mixture was then poured into... Figure 1 In the molding assembly 103 chamber shown, cold pressing is performed at a pressure of 5 MPa for 30 seconds. The mixture is then transferred to the heating chamber and... Figure 1 As shown, the top cover 102 is placed over the chamber. Argon gas is introduced into the heating chamber, with a pressure gauge reading of 0.5 MPa, and the chamber is heated to approximately 300°C at a heating rate of 20°C / min, and held for 20 min. Subsequently, the temperature is increased to 1200°C at a heating rate of 30°C / min and held for 60 min. Then, it is slowly cooled. After removing the foam from the mold, the rigid carbon foam samples are processed into the required dimensions by sawing or other mechanical methods. Table 15 shows the performance data of rigid carbon foam with different formulations. All carbon foam samples passed the fire resistance test.

[0121] Table 15: Foam Carbon Parameters

[0122]

[0123]

[0124] Example 17

[0125] Four different precursor compositions were prepared by mixing 12.75g of component C16 (walnut shell biochar) with 2.25g each of binders B1 (alkaline lignin) and B4 (flour). Each composition was added to a ball mill or pulverizer and ground for 10 minutes. The mixture was then poured into... Figure 1 In the molding assembly 103 chamber shown, cold pressing is performed at a pressure of 5 MPa for 30 seconds. The mixture is then transferred to the heating chamber and... Figure 1 As shown, the top cover 102 is placed over the chamber. Argon gas is introduced into the heating chamber, with a pressure gauge reading of 0.5 MPa, and the chamber is heated to approximately 300°C at a heating rate of 20°C / min, and held for 20 min. Subsequently, the temperature is increased to 1200°C at a heating rate of 30°C / min and held for 60 min. Then, it is slowly cooled. After removing the foam from the mold, the rigid carbon foam samples are processed into the required dimensions by sawing or other mechanical methods. Table 16 shows the performance data of rigid carbon foam with different formulations. All carbon foam samples passed the fire resistance test.

[0126] Table 16: Foam Carbon Parameters

[0127]

[0128] Example 18

[0129] This study investigated the performance characteristics of foamed carbon produced under cold pressing using biomass and binder in different proportions. Component A1 (rice straw) and binder B1 (alkaline lignin) were mixed according to the proportions shown in Table 1, with a total weight of 15g. The components were added one by one into a ball mill or pulverizer and ground for 30 minutes. The mixture was then poured into… Figure 1 In the molding assembly 103 chamber shown, cold pressing is performed at a pressure of 5 MPa for 30 seconds. The mixture is then transferred to the heating chamber and... Figure 1 The top cover 102 is placed over the chamber. Argon gas is introduced into the heating chamber at a pressure gauge reading of 0.5 MPa, and the chamber is heated to approximately 300°C at a heating rate of 30°C / min, and held for 20 min. Subsequently, the temperature is increased to 1450°C at a heating rate of 20°C / min and held for 60 min. Then, it is slowly cooled. After removing the foam from the mold, the rigid foam carbon sample is processed into the desired size by sawing or other mechanical methods. Table 17 shows the performance data of rigid foam carbon with different proportions. The data indicate that the apparent density and compressive strength increase with the increase of the B1 (alkaline lignin) ratio. Porosity gradually decreases. The lowest density is 0.31 g / cm³ when all the material is rice straw. 3Under conditions where all materials are alkaline lignin, the compressive strength reaches 51.8 MPa. All materials passed the fire resistance test.

[0130] Table 17: Parameters of Rigid Foam Carbon

[0131]

[0132] Example 19

[0133] This study investigated the performance characteristics of biomass and binder-based foamed carbon produced under hot pressing at different ratios. Component A1 (rice straw) and binder B1 (alkaline lignin) were mixed according to the ratios shown in Table 1, totaling 15g. The mixtures were added one by one to a ball mill or pulverizer and ground for 30 minutes. The mixture was then poured into… Figure 1 In the molding assembly 103 chamber shown, hot pressing was performed at 5 MPa pressure and 95°C for 30 seconds. The mixture was then transferred to the heating chamber and... Figure 1 The top cover 102 is placed over the chamber. Argon gas is introduced into the heating chamber, with a pressure gauge reading of 0.5 MPa. The chamber is heated to approximately 300°C at a heating rate of 20°C / min and held for 20 min. Subsequently, the temperature is increased to 1200°C at a heating rate of 30°C / min and held for 60 min. The chamber is then slowly cooled. After removing the foam from the mold, the rigid foam carbon sample is processed into the desired size by sawing or other mechanical methods. Table 18 shows the performance data of rigid foam carbon with different proportions. The data indicate that the apparent density and compressive strength increase with the increase of the B1 (alkaline lignin) ratio. The porosity gradually decreases. The lowest density is 0.37 g / cm³ when the entire sample is rice straw. 3 Under conditions of entirely alkaline lignin, a compressive strength of 56.1 MPa was achieved. Hot pressing of the precursor composition, compared to cold pressing, improved density and compressive strength of the rigid carbon foam.

[0134] Table 18: Parameters of Rigid Foam Carbon

[0135]

[0136] Example 20

[0137] This study investigated the performance characteristics of biomass and binders used to produce foamed carbon under hot pressing at different final temperatures. Component A1 (rice straw) totaling 12.75g and binder B1 (alkaline lignin) totaling 2.25g, totaling 15g, were added one by one to a ball mill or pulverizer and ground for 30 minutes. The mixture was then poured into... Figure 1 In the molded component 103 chamber shown, a hot-pressing treatment at 95°C was performed at a pressure of 5 MPa for 30 seconds. The mixture was then transferred to the heating chamber and... Figure 1 The top cover 102 is placed over the chamber. Argon gas is introduced into the heating chamber at a pressure gauge reading of 0.5 MPa, and the chamber is heated to approximately 300°C at a heating rate of 20°C / min, and held for 20 min. Subsequently, the temperature is increased to 400-1450°C at a heating rate of 30°C / min and held for 60 min. The chamber is then slowly cooled. After removing the foam from the mold, the rigid carbon foam sample is processed into the desired size by sawing or other machining methods. Table 19 shows the performance data of rigid carbon foam with different proportions. The data indicate that the apparent density and compressive strength increase with the increase of the B1 (alkaline lignin) ratio, while the porosity gradually decreases. Compared with cold pressing, hot pressing of the precursor composition can improve the density and compressive strength of the rigid carbon foam.

[0138] Table 19 Rigid Foamed Carbon

[0139]

[0140]

[0141] Example 21

[0142] Five precursor compositions were prepared by mixing 12.75g each of components A1-A5 (straw-based) with 2.25g of binder B1 (alkaline lignin). These were then added one by one to a ball mill or pulverizer and ground for 30 minutes. The mixture was then poured into... Figure 1 In the molding assembly 103 chamber shown, cold pressing is performed at a pressure of 5 MPa for 30 seconds. The mixture is then transferred to the heating chamber and... Figure 1 As shown, the top cover 102 is placed over the chamber. Argon gas is introduced into the heating chamber, with a pressure gauge reading of 0.5 MPa. The chamber is heated to approximately 300°C at a heating rate of 20°C / min and held for 20 min. Subsequently, the temperature is increased to 1200°C at a heating rate of 30°C / min and held for 60 min. The chamber is then slowly cooled. After removing the foam from the mold, the rigid carbon foam samples are processed into the desired dimensions by sawing or other machining methods. Table 4 shows the performance data of rigid carbon foam with different proportions. Table 20 shows the theoretical data for rigid carbon foam at different temperatures, and all carbon foam samples passed the fire resistance test.

[0143] Table 20: Foam Carbon Parameters

[0144]

[0145] Example 22

[0146] Five precursor compositions were prepared by mixing 12.75g each of components A1-A5 (straw) with 2.25g of binder B2 (tannin) to form five precursor compositions. These were then added one by one to a ball mill or pulverizer and ground for 30 minutes. The mixture was then poured into... Figure 1 In the molding assembly 103 chamber shown, cold pressing is performed at a pressure of 5 MPa for 30 seconds. The mixture is then transferred to the heating chamber and... Figure 1 As shown, the top cover 102 is placed over the chamber. Argon gas is introduced into the heating chamber, with a pressure gauge reading of 0.5 MPa, and the chamber is heated to approximately 300°C at a heating rate of 20°C / min, and held for 20 min. Subsequently, the temperature is increased to 1200°C at a heating rate of 30°C / min and held for 60 min. Then, it is slowly cooled. After removing the foam from the mold, the rigid carbon foam samples are processed into the required dimensions by sawing or other mechanical methods. Table 21 shows the performance data of rigid carbon foam with different formulations. All carbon foam samples passed the fire resistance test.

[0147] Table 21: Foam Carbon Parameters

[0148]

[0149] Example 23

[0150] Five precursor compositions were prepared by mixing 12.75g each of components A1-A5 (straw) with 2.25g of binder B3 (starch) to form five precursor compositions. These were then added one by one to a ball mill or pulverizer and ground for 30 minutes. The mixture was then poured into... Figure 1 In the molding assembly 103 chamber shown, cold pressing is performed at a pressure of 5 MPa for 30 seconds. The mixture is then transferred to the heating chamber and... Figure 1 As shown, the top cover 102 is placed over the chamber. Argon gas is introduced into the heating chamber, with a pressure gauge reading of 0.5 MPa, and the chamber is heated to approximately 300°C at a heating rate of 20°C / min, and held for 20 min. Subsequently, the temperature is increased to 1200°C at a heating rate of 30°C / min and held for 60 min. Then, it is slowly cooled. After removing the foam from the mold, the rigid carbon foam samples are processed into the desired dimensions by sawing or other mechanical methods. Table 22 shows the performance data of rigid carbon foam with different formulations. All carbon foam samples passed the fire resistance test.

[0151] Table 22: Foam Carbon Parameters

[0152]

[0153]

[0154] Example 24

[0155] Five precursor compositions were prepared by mixing 12.75g each of components A1-A5 (straw) with 2.25g of binder B4 (flour). These were then added one by one to a ball mill or grinder and ground for 30 minutes. The mixture was then poured into... Figure 1 In the molding assembly 103 chamber shown, cold pressing is performed at a pressure of 5 MPa for 30 seconds. The mixture is then transferred to the heating chamber and... Figure 1 As shown, the top cover 102 is placed over the chamber. Argon gas is introduced into the heating chamber, with a pressure gauge reading of 0.5 MPa, and the chamber is heated to approximately 300°C at a heating rate of 20°C / min, and held for 20 min. Subsequently, the temperature is increased to 1200°C at a heating rate of 30°C / min and held for 60 min. Then, it is slowly cooled. After removing the foam from the mold, the rigid carbon foam samples are processed into the required dimensions by sawing or other mechanical methods. Table 23 shows the performance data of rigid carbon foam with different formulations. All carbon foam samples passed the fire resistance test.

[0156] Table 23: Foam Carbon Parameters

[0157]

[0158] Example 25

[0159] Component A6 (rice husk) was mixed at 12.75g each with binders B1 (alkaline lignin) and B4 (flour) totaling 2.25g to form three different precursor compositions. These were then added one by one to a ball mill or grinder and ground for 30 minutes. The mixture was then poured into... Figure 1 In the molding assembly 103 chamber shown, cold pressing is performed at a pressure of 5 MPa for 30 seconds. The mixture is then transferred to the heating chamber and... Figure 1 As shown, the top cover 102 is placed over the chamber. Argon gas is introduced into the heating chamber, with a pressure gauge reading of 0.5 MPa, and the chamber is heated to approximately 300°C at a heating rate of 20°C / min, and held for 20 min. Subsequently, the temperature is increased to 1200°C at a heating rate of 30°C / min and held for 60 min. Then, it is slowly cooled. After removing the foam from the mold, the rigid carbon foam samples are processed into the desired dimensions by sawing or other machining methods. Table 24 shows the performance data of rigid carbon foam with different proportions. All carbon foam samples passed the fire resistance test.

[0160] Table 24: Foam Carbon Parameters

[0161]

[0162] Example 26

[0163] Component A7 (pine wood powder) was mixed at 12.75g each with binders B1 (alkaline lignin) and B4 (flour) at a total of 2.25g to form three different precursor compositions. These were then added one by one to a ball mill or pulverizer and ground for 30 minutes. The mixture was then poured into... Figure 1 In the molding assembly 103 chamber shown, cold pressing is performed at a pressure of 5 MPa for 30 seconds. The mixture is then transferred to the heating chamber and... Figure 1 As shown, the top cover 102 is placed over the chamber. Argon gas is introduced into the heating chamber, with a pressure gauge reading of 0.5 MPa, and the chamber is heated to approximately 300°C at a heating rate of 20°C / min, and held for 20 min. Subsequently, the temperature is increased to 1200°C at a heating rate of 30°C / min and held for 60 min. Then, it is slowly cooled. After removing the foam from the mold, the rigid carbon foam samples are processed into the desired dimensions by sawing or other mechanical methods. Table 25 shows the performance data of rigid carbon foam with different proportions. All carbon foam samples passed the fire resistance test.

[0164] Table 25: Foam Carbon Parameters

[0165]

[0166]

[0167] Example 27

[0168] Mix 15g of component A8 (biogas residue) with 50ml of binder B5 (biogas slurry), and dry in a drying oven at 90 degrees Celsius to obtain 12-16g of solid mixture. Grind in a ball mill or pulverizer for 30 minutes. Pour the mixture into... Figure 1 In the molding assembly 103 chamber shown, cold pressing is performed at a pressure of 5 MPa for 30 seconds. The mixture is then transferred to the heating chamber and... Figure 1 The top cover 102 is placed over the chamber. Argon gas is introduced into the heating chamber, with a pressure gauge reading of 0.5 MPa. The chamber is heated to approximately 300°C at a heating rate of 30°C / min and held for 20 min. Subsequently, the temperature is increased to 1450°C at a heating rate of 20°C / min and held for 60 min. The mixture is then slowly cooled. After removing the foam from the mold, performance tests are performed, revealing an apparent density of 0.50 g / cm³, a porosity of 65.50%, and a compressive strength of approximately 32.45 MPa.

[0169] Example 28

[0170] Five precursor compositions were prepared by mixing 12.75g each of components A9-A13 (distillers' grains) with 2.25g of binder B1 (alkaline lignin) to form five precursor compositions. These were then added one by one to a ball mill or pulverizer and ground for 30 minutes. The mixture was then poured into... Figure 1 In the molding assembly 103 chamber shown, cold pressing is performed at a pressure of 5 MPa for 30 seconds. The mixture is then transferred to the heating chamber and... Figure 1 As shown, the top cover 102 is placed over the chamber. Argon gas is introduced into the heating chamber, with a pressure gauge reading of 0.5 MPa, and the chamber is heated to approximately 300°C at a heating rate of 20°C / min, and held for 20 min. Subsequently, the temperature is increased to 1200°C at a heating rate of 30°C / min and held for 60 min. The chamber is then slowly cooled. After removing the foam from the mold, the rigid carbon foam sample is processed into the desired size by sawing or other mechanical methods. Table 26 shows the performance data of rigid carbon foam with different proportions. Table 10 shows the theoretical data for rigid carbon foam at different temperatures, and all carbon foam samples passed the fire resistance test.

[0171] Table 26: Foam Carbon Parameters

[0172]

[0173]

[0174] Example 29

[0175] Five precursor compositions were prepared by mixing 12.75g each of components A9-A13 (distillers' grains) with 2.25g of binder B2 (tannins) to form five precursor compositions. These were then added one by one to a ball mill or grinder and ground for 30 minutes. The mixture was then poured into… Figure 1 In the molding assembly 103 chamber shown, cold pressing is performed at a pressure of 5 MPa for 30 seconds. The mixture is then transferred to the heating chamber and... Figure 1 As shown, the top cover 102 is placed over the chamber. Argon gas is introduced into the heating chamber, with a pressure gauge reading of 0.5 MPa, and the chamber is heated to approximately 300°C at a heating rate of 20°C / min, and held for 20 min. Subsequently, the temperature is increased to 1200°C at a heating rate of 30°C / min and held for 60 min. Then, it is slowly cooled. After removing the foam from the mold, the rigid carbon foam samples are processed into the desired dimensions by sawing or other mechanical methods. Table 27 shows the performance data of rigid carbon foam with different formulations. All carbon foam samples passed the fire resistance test.

[0176] Table 27: Foam Carbon Parameters

[0177]

[0178] Example 30

[0179] Five precursor compositions were prepared by mixing 12.75g each of components A9-A13 (distillers' grains) with 2.25g of binder B3 (starch) to form five precursor compositions. These were then added one by one to a ball mill or grinder and ground for 30 minutes. The mixture was then poured into... Figure 1 In the molding assembly 103 chamber shown, cold pressing is performed at a pressure of 5 MPa for 30 seconds. The mixture is then transferred to the heating chamber and... Figure 1 As shown, the top cover 102 is placed over the chamber. Argon gas is introduced into the heating chamber, with a pressure gauge reading of 0.5 MPa, and the chamber is heated to approximately 300°C at a heating rate of 20°C / min, and held for 20 min. Subsequently, the temperature is increased to 1200°C at a heating rate of 30°C / min and held for 60 min. Then, it is slowly cooled. After removing the foam from the mold, the rigid carbon foam samples are processed into the desired dimensions by sawing or other mechanical methods. Table 28 shows the performance data of rigid carbon foam with different formulations. All carbon foam samples passed the fire resistance test.

[0180] Table 28: Foam Carbon Parameters

[0181]

[0182] Example 31

[0183] Five precursor compositions were prepared by mixing 12.75g each of components A9-A13 (distillers' grains) with 2.25g of binder B4 (flour). These were then added one by one to a ball mill or grinder and ground for 30 minutes. The mixture was then poured into... Figure 1 In the molding assembly 103 chamber shown, cold pressing is performed at a pressure of 5 MPa for 30 seconds. The mixture is then transferred to the heating chamber and... Figure 1 As shown, the top cover 102 is placed over the chamber. Argon gas is introduced into the heating chamber, with a pressure gauge reading of 0.5 MPa. The chamber is heated to approximately 300°C at a heating rate of 20°C / min and held for 20 min. Subsequently, the temperature is increased to 1200°C at a heating rate of 30°C / min and held for 60 min. The chamber is then slowly cooled. After removing the foam from the mold, the rigid carbon foam samples are processed into the desired dimensions by sawing or other machining methods. Table 29 shows the performance data of rigid carbon foam with different formulations. All carbon foam samples passed the fire resistance test.

[0184] Table 29: Foam Carbon Parameters

[0185]

[0186] Example 32

[0187] Four different precursor compositions were prepared by mixing 12.75g of component A14 (bamboo) with 2.25g each of binders B1 (alkaline lignin) and B4 (flour). These were then added one by one to a ball mill or pulverizer and ground for 30 minutes. The mixture was then poured into... Figure 1 In the molding assembly 103 chamber shown, cold pressing is performed at a pressure of 5 MPa for 30 seconds. The mixture is then transferred to the heating chamber and... Figure 1 As shown, the top cover 102 is placed over the chamber. Argon gas is introduced into the heating chamber, with a pressure gauge reading of 0.5 MPa, and the chamber is heated to approximately 300°C at a heating rate of 20°C / min, and held for 20 min. Subsequently, the temperature is increased to 1200°C at a heating rate of 30°C / min and held for 60 min. Then, it is slowly cooled. After removing the foam from the mold, the rigid carbon foam samples are processed into the desired dimensions by sawing or other mechanical methods. Table 30 shows the performance data of rigid carbon foam with different proportions. All carbon foam samples passed the fire resistance test.

[0188] Table 30: Foam Carbon Parameters

[0189]

[0190] Example 33

[0191] Four different precursor compositions were prepared by mixing 12.75g of component A14 (corn cob) with 2.25g each of binders B1 (alkaline lignin) and B4 (flour). These were then added one by one to a ball mill or grinder and ground for 30 minutes. The mixture was then poured into... Figure 1 In the molding assembly 103 chamber shown, cold pressing is performed at a pressure of 5 MPa for 30 seconds. The mixture is then transferred to the heating chamber and... Figure 1 The top cover 102 is placed over the chamber. Nitrogen gas is introduced into the heating chamber at a pressure gauge reading of 0.5 MPa, and the chamber is heated to approximately 300°C at a heating rate of 20°C / min, and held for 20 min. Subsequently, the temperature is increased to 1200°C at a heating rate of 30°C / min and held for 60 min. The chamber is then slowly cooled. After removing the foam from the mold, the rigid carbon foam samples are processed into the desired dimensions by sawing or other machining methods. Table 31 shows the performance data of rigid carbon foam with different formulations. All carbon foam samples passed the fire resistance test.

[0192] Table 31: Foam Carbon Parameters

[0193]

[0194]

[0195] Example 34

[0196] Four different precursor compositions were formed by mixing 12.75g of component A16 (walnut shell powder) with 2.25g each of binders B1 (alkaline lignin) and B4 (flour). These were then added one by one to a ball mill or pulverizer and ground for 30 minutes. The mixture was then poured into... Figure 1 In the molding assembly 103 chamber shown, cold pressing is performed at a pressure of 5 MPa for 30 seconds. The mixture is then transferred to the heating chamber and... Figure 1 The top cover 102 is placed over the chamber. Nitrogen gas is introduced into the heating chamber at a pressure gauge reading of 0.5 MPa, and the chamber is heated to approximately 300°C at a heating rate of 20°C / min, and held for 20 min. Subsequently, the temperature is increased to 1200°C at a heating rate of 30°C / min and held for 60 min. The chamber is then slowly cooled. After removing the foam from the mold, the rigid carbon foam samples are processed into the desired dimensions by sawing or other machining methods. Table 32 shows the performance data of rigid carbon foam with different formulations. All carbon foam samples passed the fire resistance test.

[0197] Table 32: Foam Carbon Parameters

[0198]

[0199] Application Experiment Example 1

[0200] Embodiment 21 of the present invention can be used entirely as a building material, providing thermal insulation, sound insulation, and structural support for buildings. Its chemical composition includes a fixed carbon content of 85-95%, ash content of 5-10%, and volatile matter ≤1%. Its bulk density is 0.50-0.80 g / cm³. 3 Apparent porosity: 30-50%. Room temperature compressive strength: ≥25-40MPa. Thermal conductivity (1000℃): 0.1-1W / m·K. Strong resistance to acidic and alkaline slags at high temperatures, and excellent thermal shock resistance.

[0201] Application Experiment Example 2

[0202] The rice straw and alkaline lignin foam carbon at 400℃ in Experimental Example 20 of this invention can be used as a soil heavy metal enrichment device. The foam carbon material has a high specific surface area and a density of 0.3-1.5 cm². 3 The surface has a pore volume of / g, with a pore size distribution encompassing micropores, mesopores, and macropores: micropores facilitate the adsorption of small molecular ions, mesopores promote the diffusion and binding of metal ions, and macropores provide rapid transport channels. The surface contains oxygen-containing functional groups such as hydroxyl, carboxyl, and carbonyl groups, which can interact with Pb. 2+ Cu 2+ Cr 6+Heavy metal ions undergo complexation or electrostatic interactions, resulting in highly efficient adsorption. Experiments have shown that this type of foamed carbon effectively adsorbs Pb... 2+ The adsorption capacity can reach 100-250 mg / g, for Cu 2+ The concentration is 80-200 mg / g, for Cr 6+ With an adsorption capacity of 50-150 mg / g, and retaining 70-90% of its adsorption performance after acid washing or heat treatment regeneration, it exhibits good recycling potential and is suitable for environmental applications such as heavy metal wastewater treatment. The adsorbed foam carbon can also be enriched by incineration.

[0203] Application Experiment Example 3

[0204] In addressing water pollution, Example 34 can be used as a matrix for water pollution filtration. The biomass-based foamed carbon material possesses a high specific surface area and abundant pore structure, enabling it to effectively adsorb Pb from water. 2+ Cu 2+ Cr 6+ It removes heavy metal ions with a removal rate of 85%-95%, and also exhibits a removal efficiency of over 95% for organic dyes such as methylene blue, and over 80% for antibiotic pollutants such as tetracycline. Furthermore, through fixed-bed application, it can reduce ammonia nitrogen concentration by over 70%, and after modification with metal oxides, the removal rate of phosphate can also reach over 90%. After acid washing or organic solvent regeneration, this foamed carbon can maintain a removal performance of over 85% even after multiple cycles, indicating its broad-spectrum pollution control capabilities and good regenerability. It can be used as a functional base material in water pollution treatment, suitable for industrial wastewater treatment, domestic sewage purification, and environmental remediation.

[0205] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0206] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing biomass-based rigid foam carbon, characterized in that, Includes the following steps: (1) Biochar was prepared from biomass raw materials through pretreatment; (2) Mix biochar or biomass raw materials with binder, and then grind and press to obtain a precursor composition; (3) The precursor composition is transferred to the heating chamber, then an inert gas is introduced, the pressure is controlled, and the mixture is heated by gradient and cooled to obtain the rigid foam carbon.

2. The method for preparing biomass-based rigid foam carbon according to claim 1, characterized in that, The biomass raw materials mentioned in step (1) include any one of the following: corn stalks, soybean stalks, wheat stalks, rice straw, reed stalks, rice husks, pine powder, bamboo, corn cobs, walnut shell powder, biogas residue, and distiller's grains.

3. The method for preparing biomass-based rigid foam carbon according to claim 2, characterized in that, The fermentation tanks include any one of corn fermentation tanks, glutinous rice fermentation tanks, sorghum fermentation tanks, wheat fermentation tanks, and barley fermentation tanks.

4. The method for preparing biomass-based rigid foam carbon according to claim 1, characterized in that, The pretreatment mentioned in step (1) is one of the following: pyrolysis carbonization, hydrothermal carbonization, microwave carbonization, activation carbonization, baking carbonization, and gasification residual carbonization.

5. The method for preparing biomass-based rigid foam carbon according to claim 1, characterized in that, The adhesive mentioned in step (2) is one of alkaline lignin, tannin, starch, flour, biogas slurry and bio-oil; the adhesive accounts for 0-100% of the total weight of the mixture.

6. The method for preparing biomass-based rigid foam carbon according to claim 1, characterized in that, The grinding in step (2) is performed by ball milling or pulverizing for 30-300 min; the pressing pressure is 0.1-30 MPa, the grinding is performed until the particle size is 0.1-200 μm, and the pressing time is 5-180 s; the pressing includes cold pressing or hot pressing, and the hot pressing temperature is 20-100℃.

7. The method for preparing biomass-based rigid foam carbon according to claim 1, characterized in that, The inert atmosphere mentioned in step (3) is nitrogen, argon or helium.

8. The method for preparing biomass-based rigid foam carbon according to claim 1, characterized in that, The pressure mentioned in step (3) is 0-1 MPa.

9. The method for preparing biomass-based rigid foam carbon according to claim 1, characterized in that, The gradient heating is as follows: first, the temperature is increased to 300-450℃ at a rate of 0.1-40℃ / min and held for 10-60min, then heated to 450-1000℃ and held for 60-90min.

10. The rigid foam carbon prepared by the method of any one of claims 1-9 can be used as a heat insulation, sound insulation and load-bearing material in buildings, a matrix material for water purifier filter cartridges, or as a carrier for adsorbing heavy metal pollution in soil and a carrier for treating water pollution.

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