A method for high-value utilization of kitchen waste and waste plastics

Abstract

This invention discloses a method for the high-value utilization of kitchen waste and waste plastics, belonging to the field of solid waste resource utilization and environmental protection technology. This invention utilizes the synergistic conversion characteristics of kitchen waste and waste plastics, achieving high-value utilization of mixed solid waste through a co-hydrothermal carbonization process. By introducing anhydrous ethanol to pre-wet and disperse the surface of the waste plastics before co-hydrothermal carbonization, the problem of traditional plastics being unable to directly participate in hydrothermal reactions is avoided, reducing complex sorting and energy-intensive pretreatment steps. This invention also introduces iron salts as Lewis acid catalysts and structure inducers during the hydrothermal carbonization process, promoting the dehydration, condensation, and aromatization reactions of biomass components through in-situ catalysis. Combined with subsequent pyrolysis and acid washing, iron-based substances are effectively removed, thereby releasing and constructing a rich pore structure, ultimately obtaining a porous carbon material with high specific surface area and good porosity.

Description

Technical Field

[0001] This invention belongs to the field of solid waste resource utilization and environmental protection technology, and in particular relates to a method for high-value utilization of kitchen waste and waste plastics. Background Technology

[0002] Food waste (FW) accounts for approximately 50% of mixed household waste in China, and due to the sheer volume of household waste, the annual amount of food waste generated exceeds 100 million tons. Globally, the growth rate of food waste is approximately 8.98%. Food waste is a metal-free, semi-stable mixture containing high moisture content, non-degradable organic matter, nutrients, minerals, and microbial cells. With proper treatment, it can be transformed into valuable resources, providing a solution to the current energy shortage.

[0003] Plastics are widely used in many fields due to their low cost, ease of molding, durability, and light weight. However, most plastics are difficult to degrade in nature, causing plastic waste to persist in the environment for a long time. Increasing amounts of plastic waste are appearing in soil, lakes, rivers, and marine ecosystems, causing serious environmental pollution and ecological harm. Furthermore, although plastics do not degrade completely quickly, large plastic products break down into tiny fragments under the influence of ecological factors. Microplastics (plastic particles smaller than 5 mm) have been found in seafood, beverages, and even common table salt, leading to plastic pollution entering the human food chain. Humans ingest approximately 81,000-123,000 microplastics annually through food; these plastics entering the human body can seriously affect health and even induce cancer. Without intervention, plastic waste will have adverse effects on ecosystems, human health, and climate change. Therefore, how to achieve high-value utilization of kitchen waste and waste plastics has become an urgent technical problem to be solved in this field. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention proposes a method for the high-value utilization of kitchen waste and waste plastics.

[0005] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a method for the high-value utilization of kitchen waste and waste plastics, comprising the following steps: (1) Mix kitchen waste and waste plastics and add anhydrous ethanol to obtain a wetted solid; (2) The wetted solid and the iron salt are mixed, and then water is added to obtain a mixed slurry; (3) The mixed slurry is subjected to co-hydrothermal carbonization and drying to obtain hydrothermal carbon; (4) The hydrothermal carbon and activator are mixed and then pyrolyzed, and then acid washed to obtain porous carbon material.

[0006] Furthermore, in step (1), the mass ratio of kitchen waste to waste plastic is 8:2.

[0007] Further, in step (1), the particle size of the kitchen waste is 80 mesh; the particle size of the waste plastic is 100 mesh; and the waste plastic is waste polyethylene from household waste.

[0008] Furthermore, in step (1), the ratio of anhydrous ethanol to waste plastic is 6 mL: 2 g.

[0009] Further, in step (2), the ratio of the iron salt to the total mass of kitchen waste and waste plastic is 1:1; the iron salt is selected from FeCl3·6H2O.

[0010] Further, in step (3), the solid-liquid ratio of the co-hydrothermal carbonization is 1:10, the temperature of the co-hydrothermal carbonization is 200℃, and the holding time of the co-hydrothermal carbonization is 1.5h.

[0011] Further, in step (4), the mass ratio of the hydrothermal carbon to the activator is 1:1; the activator is selected from K2CO3.

[0012] Furthermore, in step (4), the pyrolysis temperature is 800℃ and the holding time is 1h.

[0013] Further, in step (4), the acid used for pickling is hydrochloric acid, and the concentration of the hydrochloric acid is 2 mol / L; the solid-liquid ratio of the pickling is 1:20, and the pickling time is 1 h.

[0014] The present invention also provides a porous carbon material, which is prepared according to the method described above.

[0015] Compared with the prior art, the present invention has the following advantages and technical effects: This invention utilizes the synergistic conversion characteristics of kitchen waste and waste plastics to achieve high-value utilization of mixed solid waste through a co-hydrothermal carbonization process. By introducing anhydrous ethanol to pre-wet and disperse the surface of waste plastics before co-hydrothermal carbonization, the dispersibility of waste plastics in the aqueous system is effectively improved, and the aggregation and phase separation of plastic particles are inhibited. This promotes full contact and interfacial reaction between waste plastics and biomass hydrolysis intermediates, avoiding the problem that traditional plastics cannot directly participate in hydrothermal reactions. It also reduces complex sorting and high-energy-consuming pretreatment steps, providing a green and sustainable solution for the resource utilization of mixed solid waste.

[0016] This invention also introduces iron salts as Lewis acid catalysts and structure inducers during the hydrothermal carbonization process. Through in-situ catalysis, it promotes the dehydration, condensation, and aromatization reactions of biomass components, forming uniformly dispersed iron-based intermediates within the carbon precursor. Simultaneously, with the aid of ethanol dispersion, the iron salts can act more uniformly on the food waste-waste plastic composite system, enhancing the structural synergistic effect. Combined with subsequent pyrolysis and acid washing treatments, iron-based substances are effectively removed, thereby releasing and constructing a rich porous structure, ultimately yielding a product with a high specific surface area (>800 m²). 2 ·g -1 ) and relatively good porosity (>0.57cm) 3 ·g -1 Porous carbon materials.

[0017] The method provided by this invention features a simple process flow, mild and highly controllable reaction conditions. Ethanol is used only as a pre-wetting and dispersion medium in small quantities and is not used as the main reaction solvent, ensuring high safety. The hydrothermal carbonization and pyrolysis processes are short, and the subsequent activator dosage is low, which can reduce chemical reagent consumption and environmental burden while ensuring a high specific surface area. This invention fully utilizes two types of low-value waste resources: kitchen waste and waste plastics. It has low preparation costs, good product stability, and good scalability, making it suitable for large-scale production and application in fields such as adsorption materials, energy storage electrode materials, and catalyst supports. Attached Figure Description

[0018] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a process flow diagram of the method for high-value utilization of kitchen waste and waste plastics in Example 1; Figure 2 The image shows the FT-IR spectrum of the hydrothermal carbon sample prepared in Comparative Example 1, where F2P8-200-1.5h represents the mass ratio of kitchen waste to waste plastics = 2:8, F5P5-200-1.5h represents the mass ratio of kitchen waste to waste plastics = 5:5, and F8P2-200-1.5h represents the mass ratio of kitchen waste to waste plastics = 8:2. Figure 3 The image shows the FT-IR spectrum of the hydrothermal carbon sample prepared in Example 1, where F8P2-EtOH-Fe0-200-1.5h represents 0 g of ferric chloride hexahydrate, F8P2-EtOH-Fe0.5-200-1.5h represents 5 g of ferric chloride hexahydrate, and F8P2-EtOH-Fe1-200-1.5h represents 10 g of ferric chloride hexahydrate. Figure 4FT-IR images of the F8P2-EtOH-Fe1 porous carbon material prepared in Example 1 and the F8P2 porous carbon material prepared in Comparative Example 1; Figure 5 The images show the XRD patterns of the F8P2-EtOH-Fe1 porous carbon material prepared in Example 1 and the F8P2 porous carbon material prepared in Comparative Example 1. Figure 6 The figures show nitrogen adsorption-desorption isotherms and total pore size distribution of the F8P2-EtOH-Fe1 porous carbon material prepared in Example 1 and the F8P2 porous carbon material prepared in Comparative Example 1. The inset shows the nitrogen adsorption-desorption isotherm. Figure 7 The inset shows the nitrogen adsorption-desorption isotherms and the total pore size distribution of the porous carbon materials prepared with different iron salt ratios in Example 1. The inset is the nitrogen adsorption-desorption isotherm. Detailed Implementation

[0019] 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.

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] This invention provides a method for high-value utilization of kitchen waste and waste plastics, comprising the following steps: (1) Mix kitchen waste and waste plastics and add anhydrous ethanol to obtain a wetted solid; (2) The wetted solid and the iron salt are mixed, and then water is added to obtain a mixed slurry; (3) The mixed slurry is subjected to co-hydrothermal carbonization and drying to obtain hydrothermal carbon; (4) The hydrothermal carbon and activator are mixed and then pyrolyzed, and then acid washed to obtain porous carbon material.

[0022] In a preferred embodiment, in step (1), the mass ratio of kitchen waste to waste plastic is 8:2. This invention utilizes the synergistic conversion characteristics of kitchen waste and waste plastic to prepare porous carbon materials through hydrothermal carbonization and pyrolysis, achieving efficient recycling and resource utilization of waste.

[0023] In a preferred embodiment, step (1) further includes drying, crushing and sieving steps before use of the kitchen waste, and the kitchen waste powder with a particle size of 80 mesh is obtained after sieving; the particle size of the waste plastic is 100 mesh; the waste plastic is waste polyethylene (PE) from household waste.

[0024] In a preferred embodiment, in step (1), the ratio of anhydrous ethanol to waste plastic is 6 mL: 2 g.

[0025] In a preferred embodiment, in step (2), the ratio of the iron salt to the total mass of kitchen waste and waste plastic is 1:1.

[0026] Hydrothermal carbonization is a thermochemical treatment method that uses water as the reaction medium to transform organic matter under medium-low temperature and certain pressure conditions. Its reaction system can directly process raw materials with high moisture content without requiring an energy-intensive pre-drying process. Furthermore, the reaction system exhibits strong inclusiveness during hydrothermal carbonization, enabling the synergistic transformation of multiple organic components within the same reaction environment, thus providing a possibility for the in-situ co-treatment of kitchen waste and waste plastics. However, waste plastic components generally have strong hydrophobicity and are difficult to disperse uniformly in an aqueous phase, limiting their synergistic transformation efficiency in a co-hydrothermal system. To address these issues, this invention introduces ethanol as a pre-wetting and dispersion medium. Through the wetting effect of ethanol on the surface of waste plastics, the hydrophobicity of plastic particles is significantly reduced, allowing them to be uniformly mixed with kitchen waste in an aqueous system. Meanwhile, iron salts are introduced as Lewis acid catalysts during hydrothermal carbonization to generate iron-based intermediates in situ in the reaction system. These intermediates synergistically promote the dehydration, bond breaking, and rearrangement reactions of biomass components, induce the orderly evolution of carbon precursor structures, and are removed during subsequent pyrolysis and acid washing processes, thereby releasing abundant pore structures within the carbon material.

[0027] In a preferred embodiment, in step (3), the solid-liquid ratio of the co-hydrothermal carbonization is 1:10 (i.e., the ratio of the mixed slurry to water is 10g:100mL), the temperature of the co-hydrothermal carbonization is 200℃, and the holding time of the co-hydrothermal carbonization is 1.5h.

[0028] In a preferred embodiment, in step (3), the drying temperature is 105°C, and the product is dried to a constant weight.

[0029] In a preferred embodiment, in step (4), the mass ratio of the hydrothermal carbon to the activator is 1:1; the activator is selected from K2CO3.

[0030] In a preferred embodiment, in step (4), the pyrolysis temperature is 800°C, the holding time is 1 hour, and the rate of heating to the pyrolysis temperature is 5°C / min.

[0031] In a preferred embodiment, in step (4), the acid used for pickling is hydrochloric acid, the concentration of which is 2 mol / L; the solid-liquid ratio for pickling is 1:20 (g / mL), and the pickling time is 1 h.

[0032] This invention achieves efficient co-conversion of kitchen waste and waste plastics through a synergistic pathway of "ethanol pre-wetting and dispersion - in-situ induction with iron salts - co-hydrothermal carbonization - pyrolysis and acid washing," resulting in porous carbon materials with high specific surface area and good pore structure. Furthermore, the method of this invention features a simple process flow, mild conditions, and strong controllability, which not only improves the resource utilization efficiency of mixed organic waste but also provides a new technical approach for the co-conversion of biomass and waste plastics to prepare high-performance carbon materials, meeting the needs of green chemistry and sustainable development.

[0033] The present invention also provides a porous carbon material, which is prepared according to the method described above.

[0034] In this embodiment of the invention, room temperature or normal temperature refers to "25±2℃".

[0035] The elemental and industrial analyses of the kitchen waste and waste PE used in the following examples and comparative examples are shown in Table 1, and the XRF (carbon removal content) analysis of the kitchen waste used is shown in Table 2.

[0036] Table 1. Elemental and industrial analysis of kitchen waste and waste PE used in the examples and comparative examples. Table 2. XRF (Carbon Removal) Analysis of Kitchen Waste Example 1 A method for high-value utilization of kitchen waste and waste plastics, the process flow is as follows: Figure 1 The steps are as follows: (1) After drying the kitchen waste, crush it and sieve it to obtain kitchen waste powder with a particle size of 80 mesh. Select waste PE powder with a particle size of 100 mesh and weigh the raw materials according to the mass ratio of kitchen waste powder to waste PE powder of 8:2. Place the kitchen waste powder and waste PE powder in a beaker for dry mixing (total mass of 2g). Then add 6mL of anhydrous ethanol to the mixed powder to make the mixture into a wet sandy state. Stir and press to fully wet the surface of the waste plastic to obtain a wetted solid. (2) Mix 10g of the wetted solid obtained in step (1) with 0g, 5g and 10g of ferric chloride hexahydrate (FeCl3·6H2O), respectively, and then mix with 60mL of deionized water and stir for 30min to obtain a mixed slurry; (3) The mixed slurry obtained in step (2) was transferred to a polytetrafluoroethylene-lined reactor. Water was used as the reaction medium, and the solid-liquid ratio was controlled at 1:10 (g / mL). The hydrothermal reaction was carried out at 200℃ for 1.5h. After the reaction was completed, the mixture was naturally cooled to room temperature. The liquid phase in the hydrothermal reaction product was then poured out directly. The remaining wet solid was not filtered or washed. It was directly dried in an oven at 105℃ to constant weight to obtain hydrothermal carbon samples (referred to as F8P2-EtOH-Fe0-200-1.5h, F8P2-EtOH-Fe0.5-200-1.5h, and F8P2-EtOH-Fe1-200-1.5h). (4) Grind the hydrothermal carbon sample obtained in step (3) into powder, take 2g of hydrothermal carbon sample powder and 2g of K2CO3, mix them and place them in a ceramic boat of a tube furnace, and heat them in a nitrogen atmosphere (flow rate of 100mL·min). -1 At 5℃·min -1 The temperature was increased to 800℃ at a certain rate and held for 1 hour. After the reaction was completed, the temperature was naturally cooled to room temperature to obtain an iron-carbon material. (5) The iron-containing carbon material obtained in step (4) is added to a hydrochloric acid solution with a concentration of 2 mol / L and a solid-liquid ratio of 1:20 (g / mL). The mixture is then magnetically stirred and acid-washed for 1 h at room temperature to remove the iron-based intermediate. Subsequently, the mixture is repeatedly washed with deionized water until the washing solution is neutral. Finally, it is dried at 105 °C to constant weight to obtain porous carbon materials (denoted as F8P2-EtOH-Fe0, F8P2-EtOH-Fe0.5, and F8P2-EtOH-Fe1).

[0037] Comparative Example 1 A method for high-value utilization of kitchen waste and waste plastics includes the following steps: (1) Dry the kitchen waste, crush it and sieve it to obtain kitchen waste powder with a particle size of 80 mesh. Select waste PE powder with a particle size of 100 mesh and weigh the raw materials according to the mass ratio of kitchen waste powder to waste PE powder of 2:8, 5:5 and 8:2 for later use. (2) The kitchen waste powder weighed in step (1) and the waste PE powder were placed in a beaker and mixed. Then the mixture was transferred to a polytetrafluoroethylene-lined reactor. Water was used as the reaction medium and the solid-liquid ratio was controlled at 1:10 (g / mL). The hydrothermal reaction was carried out at 200℃ for 1.5h. After the reaction was completed, the mixture was naturally cooled to room temperature. The hydrothermal reaction products were then filtered and washed in sequence. Finally, they were dried in an oven at 105℃ to constant weight to obtain hydrothermal carbon samples (referred to as F2P8-200-1.5h, F5P5-200-1.5h, and F8P2-200-1.5h). (3) Grind the hydrothermal carbon sample obtained in step (2) into powder, take 2g of hydrothermal carbon sample powder and 2g of K2CO3, mix them and place them in a ceramic boat of a tube furnace, and heat them in a nitrogen atmosphere (flow rate of 100mL·min). -1 At 5℃·min -1 The temperature was increased to 800℃ and held for 1 hour. After the reaction was completed, the temperature was naturally cooled to room temperature to obtain porous carbon materials (denoted as F2P8, F5P5, and F8P2).

[0038] Comparative Example 2 A method for high-value utilization of kitchen waste and waste plastics includes the following steps: (1) After drying the kitchen waste, crush it and sieve it to obtain kitchen waste powder with a particle size of 80 mesh. Select waste PE powder with a particle size of 100 mesh and weigh the raw materials according to the mass ratio of kitchen waste powder to waste PE powder of 8:2. Place the kitchen waste powder and waste PE powder in a beaker for dry mixing (total mass of 10g). Then add 6mL of anhydrous ethanol to the mixed powder to make the mixture into a wet sandy state. Stir and press to fully wet the surface of the waste plastic to obtain a wetted solid. (2) The wetted solid obtained in step (1) was transferred to a polytetrafluoroethylene-lined reactor. Water was used as the reaction medium, and the solid-liquid ratio was controlled at 1:10 (g / mL). The hydrothermal reaction was carried out at 200℃ for 1.5h. After the reaction was completed, the product was naturally cooled to room temperature. Then the hydrothermal reaction product was filtered and washed in sequence, and then dried in an oven at 105℃ to constant weight to obtain a hydrothermal carbon sample. (3) Grind the hydrothermal carbon sample obtained in step (2) into powder, take 2g of hydrothermal carbon sample powder and 2g of K2CO3, mix them and place them in a ceramic boat of a tube furnace, and heat them in a nitrogen atmosphere (flow rate of 100mL·min). -1 At 5℃·min -1 The temperature was increased to 800℃ and held for 1 hour. After the reaction was completed, the temperature was naturally cooled to room temperature to obtain a porous carbon material (denoted as FW / PE-EtOH).

[0039] Comparative Example 3 A method for high-value utilization of kitchen waste and waste plastics includes the following steps: (1) After drying the kitchen waste, crush it and sieve it to obtain kitchen waste powder with a particle size of 80 mesh. Select waste PE powder with a particle size of 100 mesh and weigh the raw materials according to the mass ratio of kitchen waste powder to waste PE powder of 8:2. Place the kitchen waste powder and waste PE powder in a beaker for dry mixing to obtain mixed dry material. Then weigh ferric chloride hexahydrate (FeCl3·6H2O) according to the ratio of the total mass of kitchen waste powder and waste PE powder to the mass of iron salt of 1:1, add it to deionized water to dissolve and prepare iron salt aqueous solution. Slowly add the obtained iron salt aqueous solution to the above mixed dry material and stir magnetically for 30 min at room temperature to obtain mixed slurry. (2) The mixed slurry obtained in step (1) was transferred to a polytetrafluoroethylene-lined reactor. Water was used as the reaction medium, and the solid-liquid ratio was controlled at 1:10 (g / mL). The hydrothermal reaction was carried out at 200℃ for 1.5h. After the reaction was completed, the mixture was naturally cooled to room temperature. Then the liquid phase in the hydrothermal reaction product was directly poured out. The remaining wet solid was not filtered or washed. It was directly dried in an oven at 105℃ to constant weight to obtain a hydrothermal carbon sample. (3) Grind the hydrothermal carbon sample obtained in step (2) into powder, take 2g of hydrothermal carbon sample powder and 2g of K2CO3, mix them and place them in a ceramic boat of a tube furnace, and heat them in a nitrogen atmosphere (flow rate of 100mL·min). -1 At 5℃·min -1 The temperature was increased to 800℃ at a certain rate and held for 1 hour. After the reaction was completed, the temperature was naturally cooled to room temperature to obtain an iron-carbon material. (4) The iron-containing carbon material obtained in step (3) is first washed with deionized water, then washed with 2 mol / L hydrochloric acid solution to remove the iron-based intermediate, and finally washed again with a large amount of deionized water until the washing solution is neutral. The resulting solid is dried at 105°C to constant weight to obtain porous carbon material (denoted as F8P2-Fe1).

[0040] The FT-IR spectrum of the hydrothermal carbon sample prepared in Comparative Example 1 is shown below. Figure 2 Among them, F2P8-200-1.5h has a mass ratio of kitchen waste to waste plastic of 2:8, F5P5-200-1.5h has a mass ratio of kitchen waste to waste plastic of 5:5, and F8P2-200-1.5h has a mass ratio of kitchen waste to waste plastic of 8:2. Figure 2 It can be seen that when the ratio of kitchen waste to waste plastic is 8:2 (F8P2-200-1.5h), the hydrothermal charcoal will be at approximately 3400 cm³. -1 (-OH) and 1650cm -1 The characteristic absorption peak intensity at (C=O) is the most significant, indicating that this specific ratio is most conducive to retaining and constructing a high density of oxygen-containing active functional groups on the surface of hydrothermal carbon, thus obtaining hydrothermal carbon material with optimal structural performance.

[0041] The FT-IR spectrum of the hydrothermal carbon sample prepared in Example 1 is shown below. Figure 3 Wherein, F8P2-EtOH-Fe0-200-1.5h represents a dosage of 0 g of ferric chloride hexahydrate, F8P2-EtOH-Fe0.5-200-1.5h represents a dosage of 5 g of ferric chloride hexahydrate, and F8P2-EtOH-Fe1-200-1.5h represents a dosage of 10 g of ferric chloride hexahydrate. Figure 3 It can be seen that with the change of the iron introduction ratio, the strength of functional groups such as -OH, CH3 / CH2, and COC on the surface of hydrothermal carbon undergoes regular evolution, and the appearance and change of Fe-O bonds at low wavenumbers confirm that changing the iron ratio can effectively regulate the surface chemical structure of hydrothermal carbon and its complex state with iron species.

[0042] The FT-IR spectra of the F8P2-EtOH-Fe1 porous carbon material prepared in Example 1 and the F8P2 porous carbon material prepared in Comparative Example 1 are shown below. Figure 4 As can be seen from the figure, the porous carbon (F8P2-EtOH-Fe1) modified with ethanol-ferric chloride exhibits high porosity at 1100 cm⁻¹. -1 The COC functional groups at the 500-700 cm⁻¹ are significantly weakened due to catalytic deoxygenation. -1 The successful introduction of Fe-O active sites indicates that ethanol wetting and ferric chloride treatment can effectively regulate the structure of porous carbon framework and achieve metal functionalization.

[0043] The XRD patterns of the F8P2-EtOH-Fe1 porous carbon material prepared in Example 1 and the F8P2 porous carbon material prepared in Comparative Example 1 are shown below. Figure 5 As can be seen from the figure, the sample prepared without the additives (F8P2) exhibits a broad diffuse peak in the range of approximately 20~30° at 2θ, showing typical amorphous carbon structure characteristics; in the sample (F8P2-EtOH-Fe1) after ethanol wetting and ferric chloride treatment, the intensity of the (002) broad peak is weakened, and obvious diffraction peaks appear at approximately 44.7°, 52.1° and 65.1° at 2θ, indicating that ethanol wetting and ferric chloride treatment can regulate the microstructure of porous carbon.

[0044] The nitrogen adsorption-desorption isotherms and total pore size distribution diagrams of the F8P2-EtOH-Fe1 porous carbon material prepared in Example 1 and the F8P2 porous carbon material prepared in Comparative Example 1 are shown below. Figure 6 As can be seen from the figure, the synergistic treatment of ethanol and ferric chloride is beneficial to optimizing the pore structure distribution of porous carbon, forming abundant pore volume in the small pore region, thus exhibiting superior adsorption performance.

[0045] The structural properties of the porous carbon materials obtained in Example 1 and Comparative Examples 1-3 are shown in Table 3.

[0046] Table 3. Structural property analysis of the porous carbon materials obtained in Example 1 and Comparative Examples 1-3 The nitrogen adsorption-desorption isotherms and total pore size distribution diagrams of the porous carbon materials prepared with different iron salt ratios in Example 1 are shown below. Figure 7 As shown in the figure, the pore size distribution of porous carbon materials prepared with different amounts of FeCl3 additions varies significantly, indicating that the introduction of FeCl3 is beneficial to the formation of small-sized pore structures. Combined with the nitrogen adsorption-desorption isotherms in the inset, it can be seen that each sample has a certain adsorption capacity. The F8P2-EtOH-Fe0 sample shows a more significant increase in adsorption capacity in the high relative pressure region, indicating that it has more mesoporous structures; while the sample with added FeCl3 shows an increase in adsorption capacity in the low-pressure region, indicating the development of microporous structures. Overall, the results show that the addition of FeCl3 has a regulatory effect on the pore structure of porous carbon, promoting the development of pore size distribution towards micro / small mesoporous directions.

[0047] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for high-value utilization of kitchen waste and waste plastics, characterized in that, Includes the following steps: (1) Mix kitchen waste and waste plastics and add anhydrous ethanol to obtain a wetted solid; (2) The wetted solid and the iron salt are mixed, and then water is added to obtain a mixed slurry; (3) The mixed slurry is subjected to co-hydrothermal carbonization and drying to obtain hydrothermal carbon; (4) The hydrothermal carbon and activator are mixed and then pyrolyzed, and then acid washed to obtain porous carbon material.

2. The method for high-value utilization of kitchen waste and waste plastics according to claim 1, characterized in that, In step (1), the mass ratio of kitchen waste to waste plastic is 8:

2.

3. The method for high-value utilization of kitchen waste and waste plastics according to claim 1, characterized in that, In step (1), the particle size of the kitchen waste is 80 mesh; the particle size of the waste plastic is 100 mesh; and the waste plastic is waste polyethylene from household waste.

4. The method for high-value utilization of kitchen waste and waste plastics according to claim 1, characterized in that, In step (1), the ratio of anhydrous ethanol to waste plastic is 6 mL: 2 g.

5. The method for high-value utilization of kitchen waste and waste plastics according to claim 1, characterized in that, In step (2), the ratio of the iron salt to the total mass of kitchen waste and waste plastic is 1:1; the iron salt is selected from FeCl3·6H2O.

6. The method for high-value utilization of kitchen waste and waste plastics according to claim 1, characterized in that, In step (3), the solid-liquid ratio of the co-hydrothermal carbonization is 1:10, the temperature of the co-hydrothermal carbonization is 200℃, and the holding time of the co-hydrothermal carbonization is 1.5h.

7. The method for high-value utilization of kitchen waste and waste plastics according to claim 1, characterized in that, In step (4), the mass ratio of the hydrothermal carbon to the activator is 1:1; the activator is selected from K2CO3.

8. The method for high-value utilization of kitchen waste and waste plastics according to claim 1, characterized in that, In step (4), the pyrolysis temperature is 800℃ and the holding time is 1h.

9. The method for high-value utilization of kitchen waste and waste plastics according to claim 1, characterized in that, In step (4), the acid used for pickling is hydrochloric acid, and the concentration of the hydrochloric acid is 2 mol / L; the solid-liquid ratio of the pickling is 1:20, and the pickling time is 1 h.

10. A porous carbon material, characterized in that, Prepared by the method according to any one of claims 1-9.

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