Preparation method of biomass carbon source based on kitchen waste

Abstract

The invention provides a preparation method of a biomass carbon source based on kitchen waste, which comprises the following steps: crushing kitchen waste, separating grease, modifying partial bagasse adsorption slurry by using acid and ethanol, mixing with residual bagasse for fermentation, finally removing oil and performing solid-liquid separation to obtain biomass carbon source liquid, and activating the residues into a porous carbon material. According to the method, organic matters in the kitchen waste are fully recycled and converted into a high-value biomass carbon source, the bagasse is combined with the kitchen waste, on one hand, salt in the kitchen waste can be removed through the modified bagasse, on the other hand, solid residues obtained after the bagasse and slurry are fermented and degraded together are activated to obtain a porous carbon material, and the porous carbon material can be recycled. The obtained biomass carbon source liquid can be used for synchronously producing yeast protein and ethanol through fungal fermentation, is not influenced by the inhibition of kitchen waste acid-base conditions and high ammonia nitrogen, can be used for conveniently carrying out biological fermentation, and has a large-scale application prospect.

Description

Technical Field

[0001] The present invention relates to the field of food waste treatment, and more particularly to a method for preparing a biomass carbon source based on food waste. Background Art

[0002] Food waste primarily comes from the catering industry, workplace canteens, and home kitchens. Its composition is complex, primarily including rice and flour residues, vegetables, animal and vegetable oils, meat and bones, and is characterized by high moisture, oil, and salt content, as well as susceptibility to spoilage. Currently, anaerobic fermentation is the primary method of treating food waste in my country. However, due to the diverse nature of foreign matter, the wide variation in form and properties, and the low yield of resource-based products such as biogas and crude oil, food waste treatment presents challenges such as complex technical processes, high operating costs, and low resource value.

[0003] At the same time, demand for biomass carbon sources continues to grow in fields such as microbial fermentation and sewage treatment. Sewage treatment plants, in particular, face widespread nutrient imbalances in their influent. Due to insufficient carbon sources for denitrification, the process relies primarily on external carbon sources for deep denitrification. Currently, commonly used carbon sources include methanol, sodium acetate, and glucose, but these are often costly and unsustainable.

[0004] Therefore, developing biomass carbon sources using food waste as raw material can not only solve the problem of food waste disposal, but also address the high cost of adding carbon sources to sewage treatment plants, combining environmental governance with resource recycling value. However, current technologies and processes for preparing carbon sources from food waste have drawbacks such as complex preparation methods, long preparation times, poor component separation, high costs, and insufficient carbon source purity and stability. These drawbacks cannot meet the requirements of high external carbon source product content, easy biodegradation, fast reaction speed, good biological adaptability, and low price. In addition, high salt content can severely inhibit fermentation microorganisms and the resulting biomass carbon source liquid can also have an inhibitory effect when used in fungal fermentation. Therefore, further improvement and development are needed. Summary of the Invention

[0005] In view of the various deficiencies of the existing technology, in order to solve the above problems, a method for preparing a biomass carbon source based on kitchen waste is proposed, and the following technical solutions are provided: A method for preparing a biomass carbon source based on food waste comprises the following steps: S1: Crush the food waste to a particle size of ≤5mm; S2: Mixing the shredded food waste with water and subjecting it to heat treatment to separate the grease and pulp; S3: separating bagasse into bagasse A and bagasse B, crushing bagasse A to a particle size of 1-1.5 cm, immersing the bagasse A in an acid solution, washing with water until neutral, drying the bagasse, and then immersing the bagasse in an ethanol solution for microwave treatment to obtain modified bagasse, mixing the slurry with the modified bagasse, and filtering the slurry to obtain a filtered slurry; S4: mixing the filtered slurry with bagasse B having a particle size of ≤5 mm and adding the mixture with a microbial fermentation aid into a fermentation device for fermentation and degradation; S5: The fermented and degraded slurry is heated again and then subjected to secondary oil removal to obtain a deoiled slurry; S6: performing solid-liquid separation on the deoiled slurry to obtain a biomass carbon source liquid and a solid residue; S7: Mixing the solid residue with an activating agent to activate the mixture to obtain a porous carbon material.

[0006] Furthermore, the solid-liquid ratio of the crushed kitchen waste to water in step S2 is 1:(2-5).

[0007] Furthermore, in step S3, the mass ratio of bagasse A to kitchen waste is 2-4:7-10.

[0008] Furthermore, in step S3, the acid solution is an oxalic acid solution with a mass concentration of 3-5%, the immersion in the oxalic acid solution is 2-3 hours, the power of the microwave treatment is 800-1000W, and the microwave treatment time is 5-10 minutes.

[0009] Furthermore, the heat treatment temperature in step S2 is 40-60° C. and the time is 10-60 min.

[0010] Furthermore, in step S2, a centrifugal separation device is used to separate the grease and the slurry, and the centrifugal separation speed is 3000-5000 r / min and the time is 5-20 min.

[0011] Furthermore, the microbial fermentation aid in step S4 is potassium dihydrogen phosphate or magnesium sulfate, and the amount of the microbial fermentation aid added is 0.5%-1% of the mass of the slurry.

[0012] Furthermore, in step S4, nano-catalytic materials are added to the fermentation device, and the amount of the nano-catalytic materials added is 0.1%-0.3% of the mass of the slurry.

[0013] Furthermore, in step S4, the fermentation and degradation time is 6-24 hours, stirring is performed every 10-120 minutes, the stirring speed is controlled at 100-200 r / min, and the stirring time is 5-10 minutes.

[0014] Furthermore, the amount of bagasse B in step S4 is 60-80% of the mass of the filtered slurry.

[0015] Due to the adoption of the above technical solution, the beneficial technical effects of the present invention are: 1. The present invention fully recovers organic matter from food waste and converts it into a high-value biomass carbon source. Furthermore, bagasse is combined with food waste. On the one hand, the modified bagasse can remove salt from the food waste. On the other hand, the solid residue obtained after fermentation and degradation of the bagasse with a slurry is activated to obtain a porous carbon material. The obtained biomass carbon source liquid can be fermented by fungi to simultaneously produce yeast protein and ethanol, and is not affected by the acid-base conditions and high ammonia nitrogen content of food waste. This allows for relatively convenient biofermentation and has the prospect of large-scale application. 2. The carbon source of the present invention is of excellent quality. Through component separation, catalytic activation and multi-stage purification, the effective organic matter content (in terms of COD) in the carbon source is ≥60,000 mg / L. The composition is stable and can replace conventional carbon sources such as glucose and sodium acetate. It is suitable for scenarios such as microbial fermentation and denitrification. 3. Full resource utilization: The oil in the kitchen waste is prepared into biomass-based liquid fuel, and the solid residue is prepared into dispersed porous carbon materials, achieving full resource utilization of the kitchen waste without generating any three wastes and avoiding secondary pollution; 4. Reduce the pollution risk of landfill and incineration of food waste. At the same time, there is no secondary pollution in the preparation process, which contributes to the circular economy and green development. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic flow chart of a method for preparing a biomass carbon source based on food waste according to the present invention. DETAILED DESCRIPTION

[0017] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is clearly and completely described below in conjunction with the embodiments of the present invention. Based on the embodiments in this application, other similar embodiments obtained by ordinary technicians in this field without making any creative work should fall within the scope of protection of this application.

[0018] A method for preparing a biomass carbon source based on food waste comprises the following steps: S1: Crush the food waste into particles ≤ 5mm. Crush the food waste into fine particles to facilitate the subsequent mixing of the food waste and water.

[0019] S2: The shredded food waste is mixed with water and heat-treated to separate the grease and pulp. The separated grease is collected for reuse, and the pulp enters the next step of treatment.

[0020] S3: Bagasse is separated into bagasse A and bagasse B. Bagasse A is crushed to a particle size of 1-1.5 cm, immersed in an acid solution, and then washed with water until neutral. After drying, it is immersed in an ethanol solution and microwave-treated to obtain modified bagasse. The slurry and the modified bagasse are mixed and stirred, and then filtered to obtain a filtered slurry. The modified bagasse has a particle size of 1-1.5 cm, which is much larger than the fine organic particles in the slurry. This prevents the loss of organic particles in the slurry during filtration and separation. The porous structure of the bagasse provides attachment sites for fermentation bacteria, thereby accelerating the reaction rate. At the same time, the fermented carbon source liquid of food waste is rich in volatile fatty acids (VFAs), alcohols, and various trace elements. Small organic molecules such as VFAs can effectively penetrate the dense fiber structure of sugarcane bagasse. During the subsequent carbonization and activation stage, these embedded organic matter will preferentially decompose or gasify, helping to form a richer and more developed pore structure, thereby significantly increasing the specific surface area of ​​the activated carbon. Trace elements such as nitrogen, phosphorus, and sulfur are adsorbed by the sugarcane bagasse fibers during the modification process. During high-temperature carbonization, these elements are chemically embedded in the carbon skeleton, achieving in-situ heteroatom doping. Nitrogen-doped carbon materials have excellent surface polarity, electronic conductivity, and catalytic activity, which can greatly enhance the adsorption capacity and catalytic performance of activated carbon for pollutants.

[0021] S4: The filtered slurry is mixed with bagasse B having a particle size of ≤5 mm and then added to a fermentation device with a microbial fermentation aid for fermentation and degradation. The fermentation produces a high-value biomass carbon source liquid and a stabilized solid residue.

[0022] S5: The fermented and degraded slurry is heated again and subjected to secondary degreasing to produce a degreased slurry. This secondary degreasing process ensures that trace amounts of oil in the slurry are removed. The resulting oil, along with the oil separated in S2, can be used to produce biomass-based liquid fuel.

[0023] S6: The deoiled slurry is subjected to solid-liquid separation to obtain a biomass carbon source liquid and a solid residue. The separated biomass carbon source liquid has an effective organic matter content (calculated as COD) of ≥60,000 mg / L and is stable in composition. It can replace conventional carbon sources such as glucose and sodium acetate and is suitable for microbial fermentation and denitrification. The resulting biomass carbon source liquid can be fermented by fungi to simultaneously produce yeast protein and ethanol. It is not affected by the acid-base conditions and high ammonia nitrogen content of food waste, allowing for relatively convenient biofermentation and has the potential for large-scale application.

[0024] S7: The solid residue is mixed with an activating agent for activation to produce a porous carbon material. The resulting porous carbon material has a rich surface functional group. The oxygen- and nitrogen-containing functional groups introduced by the food waste greatly enhance the surface chemical activity of the activated carbon, enabling it to have an extremely high adsorption capacity and rate for heavy metal ions and organic pollutants through complexation, ion exchange, and hydrogen bonding.

[0025] Specifically, the solid-to-liquid ratio of the pulverized food waste to water in step S2 is 1:(2-5). Heat treatment is performed at a solid-to-liquid ratio of 1:(2-5). This ratio represents the maximum range of food waste that water can accommodate. Excessive food waste will push the water's carrying capacity to its limit, preventing the food waste from forming a slurry. Excessive food waste will waste water resources, and the resulting slurry will contain too little biomass carbon source, which will also burden subsequent processing.

[0026] Specifically, the mass ratio of bagasse A to food waste in step S3 is 2-4:7-10. Mixing the modified bagasse and food waste slurry at a mass ratio of 2-4:7-10 effectively reduces the salt content in the slurry through adsorption, reducing the load and difficulty of subsequent fermentation degradation.

[0027] Specifically, in step S3, the acid solution is an oxalic acid solution with a mass concentration of 3-5%. The bagasse is immersed in the oxalic acid solution for 2-3 hours. The microwave treatment power is 800-1000W, and the microwave treatment time is 5-10 minutes. Oxalic acid treatment of the bagasse effectively hydrolyzes and destroys some of the cellulose and lignin in the bagasse, rendering the originally dense fiber structure loose and porous. Microwave treatment in an ethanol solution produces a localized thermal effect, further increasing the porosity and specific surface area of ​​the bagasse. This loose and porous structure improves the bagasse's ability to absorb impurities such as salt from the slurry.

[0028] Specifically, the heat treatment temperature in step S2 is 40-60° C. and the time is 10-60 min.

[0029] Specifically, in step S2, a centrifugal separation device is used to separate the grease and the slurry, and the centrifugal separation speed is 3000-5000 r / min and the time is 5-20 minutes. The centrifugal separation speed of 3000-5000 r / min and the time of 5-20 minutes can ensure sufficient separation of the grease and the slurry.

[0030] Specifically, the microbial fermentation aid in step S4 is potassium dihydrogen phosphate or magnesium sulfate, and the amount of the microbial fermentation aid added is 0.5%-1% of the mass of the slurry. An appropriate amount of potassium dihydrogen phosphate or magnesium sulfate provides additional nutrients and trace elements for microbial fermentation.

[0031] Specifically, in step S4, nanocatalytic materials are added to the fermentation device in an amount of 0.1%-0.3% of the mass of the slurry. An appropriate amount of nanocatalytic materials has a large specific surface area and high reactivity, and is an important part of efficient fermentation.

[0032] Specifically, the fermentation and degradation time in step S4 is 6-24 hours, with stirring every 10-120 minutes, a stirring speed of 100-200 r / min, and a stirring time of 5-10 minutes. The stirring interval and stirring time of the fermentation are controlled to ensure that the bagasse and slurry are fully mixed without generating temperature gradients or concentration gradients.

[0033] Specifically, the amount of bagasse B in step S4 is 60-80% of the mass of the filtered slurry. Controlling the amount of bagasse B allows the bagasse to have excellent properties in the subsequently prepared porous carbon material.

[0034] The specific process of the present invention is as follows Figure 1 As shown: Food waste is transported to a sorting platform for screening. A combination of manual and mechanical screening processes separates solid impurities like metal and ceramic fragments, as well as non-biodegradable materials like plastics, ensuring the purity of the organic raw materials for subsequent processing. The food waste in S1-S7 below represents pure, sorted food waste.

[0035] The kitchen waste is crushed into particles ≤ 5mm; the kitchen waste is crushed into fine particles to facilitate the subsequent mixing of the kitchen waste with water so that they can fully contact each other.

[0036] The crushed food waste is mixed with water at a solid-liquid ratio of 1:(2-5) and heat treated for 10-60 minutes at a temperature of 40-60°C. After the heat treatment, the oil and grease are separated by centrifugation at a speed of 3000-5000 rpm for 5-20 minutes.

[0037] Sugarcane bagasse is divided into sugarcane bagasse A and sugarcane bagasse B. Sugarcane bagasse A is crushed to a particle size of 1-1.5 cm and then immersed in an oxalic acid solution with a mass concentration of 3-5% for 2-3 hours. After immersion, it is washed with water until neutral, dried, immersed in an ethanol solution, and microwaved at a power of 800-1000 W for 5-10 minutes to obtain a modified sugarcane bagasse. The modified sugarcane bagasse and a food waste slurry are mixed and stirred at a mass ratio of 2-4:7-10, and then filtered to obtain a filtered slurry.

[0038] The filtered slurry is mixed with 60%-80% of the slurry weight of bagasse B with a particle size of ≤5 mm, and then added to a fermentation device with 0.5%-1% of the slurry weight of potassium dihydrogen phosphate or magnesium sulfate. Furthermore, 0.1%-0.3% of the slurry weight of a nanocatalytic material is added to the fermentation device for fermentation and degradation. The fermentation device is stirred every 10-120 minutes, with a stirring speed of 100-200 r / min and a stirring time of 5-10 minutes. The fermentation time is 6-24 hours.

[0039] The slurry after fermentation degradation is heated again to perform secondary oil removal to obtain the slurry after oil removal.

[0040] The slurry after oil removal is subjected to solid-liquid separation to obtain a biomass carbon source liquid and a solid residue.

[0041] The solid residue is mixed with an activating agent to perform activation to obtain a porous carbon material.

[0042] Example 1 S1: The kitchen waste is stirred and crushed to a particle size of ≤5 mm; S2: The kitchen waste after stirring and crushing is mixed with water, and after heat treatment, oil and slurry are separated; the kitchen waste after stirring and crushing is mixed with water, the solid-liquid ratio of the kitchen waste after stirring and crushing to water is 1:3, and heat treatment is performed at a temperature of 50°C for 40 min. After heat treatment, a centrifugal separation device with a rotation speed of 4000 r / min is used to separate oil and slurry for 15 min.

[0043] S3: The bagasse is divided into bagasse A and bagasse B, the bagasse A is stirred and crushed to a particle size of 1.5 cm, then immersed in an oxalic acid solution with a mass concentration of 4% for 2.5 h, washed to neutral after immersion, dried, then immersed in an ethanol solution, and subjected to microwave treatment with a power of 900 W for 8 min to obtain modified bagasse. The modified bagasse with a mass ratio of 3:8 is mixed with the kitchen waste slurry, stirred, filtered, and then filtered slurry is obtained.

[0044] S4: The filtered slurry is mixed with bagasse B with a particle size of ≤5 mm at a mass ratio of 70% of the slurry, and 1% of the slurry mass of potassium dihydrogen phosphate or magnesium sulfate is added to the fermentation device, and 0.2% of the slurry mass of nano-catalytic material is added to the fermentation device for fermentation degradation. The fermentation device is stirred every 60 min, the stirring speed is controlled at 150 r / min, the stirring time is 8 min, and the fermentation time is 18 h.

[0045] S5: The slurry after fermentation degradation is heated again to perform secondary oil removal to obtain the slurry after oil removal; S6: The slurry after oil removal is subjected to solid-liquid separation to obtain a biomass carbon source liquid and a solid residue. S7: The solid residue is mixed with an activating agent to perform activation to obtain a porous carbon material.

[0046] Example 2 S1: The kitchen waste is stirred and crushed to a particle size of ≤5 mm; S2: The shredded food waste is mixed with water and subjected to heat treatment to separate the fat and slurry. The shredded food waste is mixed with water at a solid-to-liquid ratio of 1:5 and heat treated for 60 minutes at 60°C. After the heat treatment, the grease and slurry are separated by centrifugation at a speed of 5000 rpm for 20 minutes.

[0047] S3: Bagasse is separated into bagasse A and bagasse B. Bagasse A is crushed to a particle size of 1.5 cm and immersed in a 5% oxalic acid solution for 3 hours. After immersion, the bagasse is washed with water until neutral, dried, immersed in an ethanol solution, and microwaved at 1000 W for 10 minutes to obtain a modified bagasse. The modified bagasse is mixed with a food waste slurry at a mass ratio of 4:7, stirred, and filtered to obtain a filtered slurry.

[0048] S4: The filtered slurry is mixed with 80% of the slurry mass of bagasse B with a particle size of ≤5 mm, and then added to a fermentation device with 0.5% of the slurry mass of potassium dihydrogen phosphate or magnesium sulfate. 0.3% of the slurry mass of the nanocatalytic material is also added to the fermentation device for fermentation and degradation. The fermentation device is stirred every 120 minutes at a controlled stirring speed of 200 r / min and a stirring time of 10 minutes. The fermentation time is 24 hours.

[0049] S5: The fermented and degraded slurry is heated again and then subjected to secondary oil removal to obtain a deoiled slurry; S6: performing solid-liquid separation on the deoiled slurry to obtain a biomass carbon source liquid and a solid residue; S7: Mixing the solid residue with an activating agent to activate the mixture to obtain a porous carbon material.

[0050] Example 3 S1: Crush the food waste to a particle size of ≤5mm; S2: The shredded food waste is mixed with water and subjected to heat treatment to separate the fat and slurry. The shredded food waste is mixed with water at a solid-to-liquid ratio of 1:5 and heat treated for 10 minutes at 40°C. After the heat treatment, the grease and slurry are separated by centrifugation at a speed of 3000 rpm for 5 minutes.

[0051] S3: Bagasse was separated into bagasse A and bagasse B. Bagasse A was crushed to a particle size of 1 cm and immersed in a 3% oxalic acid solution for 2.5 hours. After immersion, the bagasse was washed with water until neutral, dried, and then immersed in an ethanol solution and microwaved at 800 W for 5 minutes to obtain a modified bagasse. The modified bagasse was mixed with a food waste slurry at a mass ratio of 1:5, stirred, and filtered to obtain a filtered slurry.

[0052] S4: The filtered slurry is mixed with 60% of the slurry mass of bagasse B with a particle size of ≤5 mm, and then added to a fermentation device with 0.5% of the slurry mass of potassium dihydrogen phosphate or magnesium sulfate. 0.1% of the slurry mass of the nanocatalytic material is also added to the fermentation device for fermentation and degradation. The fermentation device is stirred every 10 minutes, with a stirring speed of 100 r / min and a stirring time of 5 minutes. The fermentation time is 6 hours.

[0053] S5: The fermented and degraded slurry is heated again and then subjected to secondary oil removal to obtain a deoiled slurry; S6: performing solid-liquid separation on the deoiled slurry to obtain a biomass carbon source liquid and a solid residue; S7: Mixing the solid residue with an activating agent to activate the mixture to obtain a porous carbon material.

[0054] Comparative Example 1 The solid-to-liquid ratio of the crushed kitchen waste to water in S2 is 1:10, and other conditions are the same as those in Example 1.

[0055] Comparative Example 2 In S3, the modified bagasse and the kitchen waste slurry at a mass ratio of 1:10 are mixed and stirred, and then filtered to obtain a filtered slurry. Other conditions are the same as in Example 1.

[0056] Comparative Example 3 In S3, the bagasse A is not modified, and the modified bagasse and the kitchen waste slurry are mixed and stirred at a mass ratio of 4:7. Other conditions are the same as those in Example 1.

[0057] Comparative Example 4 In S4, the filtered slurry was not mixed with bagasse B, and other conditions were the same as in Example 1.

[0058] The biomass carbon source liquids obtained in Examples 1-3 and Comparative Examples 1-4 were subjected to the following test 1: The biomass carbon source liquids of Examples 1-3, Comparative Examples 1-4, and glucose carbon source liquids were sterilized at 120°C for 20 min. The sterilized carbon sources were used to prepare basic fermentation medium with the same total sugar concentration. A certain amount of yeast was inoculated into the fermentation medium and shaken at 30°C and 150 rpm. The glucose carbon source liquid served as the blank control group. After 48 h of fermentation, aseptic sampling was performed and the following analysis was performed: Cell biomass (DCW): Take a certain volume of fermentation broth and centrifuge at 8000 rpm for 10 minutes. Discard the supernatant. Wash the precipitate twice with deionized water and centrifuge again. Transfer the precipitate to a weighed dry Petri dish and dry in an oven at 105°C to constant weight. After cooling, weigh the precipitate and calculate DCW (g / L).

[0059] DCW (g / L) = (drying weight - container weight) / sampling volume Metabolic ethanol production: Take 1 mL of fermentation broth and centrifuge at 12,000 rpm for 5 minutes to remove the bacteria. The supernatant is collected and quantitatively analyzed by gas chromatography (GC).

[0060] Yeast protein production: The above-mentioned bacterial sediment dried for DCW measurement was used to determine the protein content, and the test results are shown in Table 1.

[0061] Table 1 Microbial fermentation test of biomass carbon source liquid The DCW values ​​in Examples 1-3 ranged from 4.6 to 5.1 g / L, all higher than those in the blank control group. This demonstrates that the food waste-based biomass carbon source liquid can efficiently support yeast growth and reproduction. Metabolic ethanol yields ranged from 20 to 22 g / L, and yeast protein yields ranged from 2.3 to 2.5 g / L, both higher than those in the blank control group. This indicates that the resulting biomass carbon source liquid can be fermented by fungi to simultaneously produce yeast protein and ethanol, unaffected by the inhibitory effects of food waste acidity and high ammonia nitrogen. This allows for relatively convenient fermentation and has the potential for large-scale application. The DCW values ​​in Comparative Examples 1-4 ranged from 1.5 to 3.8 g / L, generally lower. This is particularly true for Comparative Example 3 (1.5 g / L), indicating that the presence of inhibitors in its carbon source severely hindered bacterial growth. The trends in metabolic ethanol and yeast protein yields are highly consistent with those of DCW. Poor bacterial growth inevitably leads to low yields of both.

[0062] The porous carbon materials obtained in Examples 1-3 and Comparative Examples 1-4 were subjected to the following Test 2: 100 mg of dried porous carbon materials from Examples 1-3, Comparative Examples 1-4, and commercial activated carbon were weighed and placed in a methylene blue solution of known concentration. The mixture was shaken on a thermostatic shaker until adsorption equilibrium was reached, and then the supernatant was centrifuged. The commercial activated carbon was used as the control group. The remaining methylene blue concentration in the solution was measured using a UV-visible spectrophotometer to calculate Q. e Qe: equilibrium adsorption capacity (mg / g); C0: initial concentration of methylene blue (mg / L); C e : methylene blue concentration after adsorption equilibrium (mg / L); V: solution volume (L); m: mass of porous carbon material (g) Table 2 Methylene blue adsorption experiment of porous carbon materials The test results, shown in Table 2, show that Examples 1-3 all exhibited superior adsorption performance compared to the control group, demonstrating that the porous carbon materials prepared by the present invention exhibit superior adsorption performance compared to commercial activated carbon materials and possess significant application prospects. The data for Comparative Examples 1-4 were generally low (150-210 mg / g). Comparative Example 4 (150 mg / g) had the worst performance, demonstrating that the preparation of porous carbon materials solely based on biomass carbon sources derived from food waste presents serious challenges, resulting in an ineffective pore structure.

[0063] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A method for preparing a biomass carbon source based on food waste, characterized in that: The following steps are involved: S1: Crush the food waste to a particle size of ≤5mm; S2: Mixing the shredded food waste with water and subjecting it to heat treatment to separate the grease and pulp; S3: separating bagasse into bagasse A and bagasse B, crushing bagasse A to a particle size of 1-1.5 cm, immersing the bagasse A in an acid solution, washing with water until neutral, drying the bagasse, and then immersing the bagasse in an ethanol solution for microwave treatment to obtain modified bagasse, mixing the slurry with the modified bagasse, and filtering the slurry to obtain a filtered slurry; S4: mixing the filtered slurry with bagasse B having a particle size of ≤5 mm and adding the mixture with a microbial fermentation aid into a fermentation device for fermentation and degradation; S5: The fermented and degraded slurry is heated again and then subjected to secondary oil removal to obtain a deoiled slurry; S6: performing solid-liquid separation on the deoiled slurry to obtain a biomass carbon source liquid and a solid residue; S7: Mixing the solid residue with an activating agent to activate the mixture to obtain a porous carbon material.

2. The method for preparing a biomass carbon source based on food waste according to claim 1, characterized in that: The solid-liquid ratio of the crushed food waste to water in step S2 is 1:(2-5).

3. The method for preparing a biomass carbon source based on food waste according to claim 1, characterized in that: In step S3, the mass ratio of bagasse A to kitchen waste is 2-4:7-10.

4. The method for preparing a biomass carbon source based on food waste according to claim 3, characterized in that: In step S3, the acid solution is an oxalic acid solution with a mass concentration of 3-5%. The sample is immersed in the oxalic acid solution for 2-3 hours. The power of the microwave treatment is 800-1000W, and the microwave treatment time is 5-10 minutes.

5. The method for preparing a biomass carbon source based on food waste according to claim 1, characterized in that: The heat treatment temperature in step S2 is 40-60° C. and the time is 10-60 min.

6. The method for preparing a biomass carbon source based on food waste according to claim 1, characterized in that: In step S2, a centrifugal separation device is used to separate the grease and the slurry, and the centrifugal separation speed is 3000-5000 r / min and the time is 5-20 min.

7. The method for preparing a biomass carbon source based on food waste according to claim 1, characterized in that: The microbial fermentation aid in step S4 is potassium dihydrogen phosphate or magnesium sulfate, and the amount of the microbial fermentation aid added is 0.5%-1% of the mass of the slurry.

8. The method for preparing a biomass carbon source based on food waste according to claim 2, characterized in that: In step S4, nano-catalytic material is further added to the fermentation device, and the amount of the nano-catalytic material added is 0.1%-0.3% of the mass of the slurry.

9. The method for preparing a biomass carbon source based on food waste according to claim 8, characterized in that: The fermentation and degradation time in step S4 is 6-24 hours, stirring is performed every 10-120 minutes, the stirring speed is controlled at 100-200 r / min, and the stirring time is 5-10 minutes.

10. The method for preparing a biomass carbon source based on food waste according to claim 7, characterized in that: The amount of bagasse B used in step S4 is 60-80% of the mass of the filtered slurry.

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