Method for co-processing of kitchen waste and agroforestry waste

Abstract

The application relates to a method for synergistically treating kitchen garbage and forestry waste, comprising: first pretreating the kitchen garbage to obtain kitchen garbage oil phase, kitchen garbage liquid phase and kitchen garbage solid phase; second pretreating the forestry waste to obtain forestry waste solid phase; mixing the forestry waste solid phase and part of the kitchen garbage liquid phase and performing high-temperature treatment to obtain mixed slurry; performing first saccharification treatment on the mixed slurry and cellulase to obtain saccharified mixed slurry; mixing the remaining kitchen garbage liquid phase and the kitchen garbage solid phase to obtain kitchen garbage mixed slurry; performing second saccharification treatment on the kitchen garbage mixed slurry and saccharifying enzyme to obtain saccharified kitchen slurry; mixing the saccharified mixed slurry and the saccharified kitchen slurry to obtain fermentation raw material; and performing biological fermentation treatment on the fermentation raw material to obtain ethanol product. The method synergistically drives waste conversion through saccharification and fermentation, and increases efficiency and production.

Description

Technical Field

[0001] This application relates to the field of solid waste resource utilization technology, and in particular to a method for the co-processing of kitchen waste and agricultural and forestry waste. Background Technology

[0002] Agricultural and forestry waste refers to agricultural residues such as straw, bran, vegetable leaves, and vegetable roots, as well as garden waste such as leaves and branches, generated during agricultural and forestry production and processing. It is rich in cellulose, hemicellulose, and lignin. Kitchen waste, on the other hand, originates from perishable waste generated from residential life, food processing, and catering services. It is rich in organic matter and oils. Currently, agricultural and forestry waste is mainly converted into fertilizer through aerobic composting, while kitchen waste is generally produced through anaerobic fermentation to generate biogas. Both existing utilization methods suffer from low added value and limited product variety. Therefore, there is an urgent need to develop a technology that can co-process both types of waste and achieve high-value transformation, breaking through the limitations of a single product pathway. Summary of the Invention

[0003] This application provides a method for the co-processing of kitchen waste and agricultural and forestry waste to solve the following technical problem: how to improve the resource utilization efficiency and product diversity of kitchen waste and agricultural and forestry waste.

[0004] In a first aspect, embodiments of this application provide a method for the co-processing of kitchen waste and agricultural and forestry waste, including:

[0005] The kitchen waste is pretreated to obtain the oil phase, liquid phase and solid phase of the kitchen waste;

[0006] The agricultural and forestry waste undergoes a second pretreatment to obtain the solid phase of the agricultural and forestry waste.

[0007] The solid phase of the agricultural and forestry waste and a portion of the liquid phase of the kitchen waste are mixed and subjected to high-temperature treatment to obtain a mixed slurry;

[0008] The mixed slurry and cellulase are subjected to a first saccharification treatment to obtain a saccharified mixed slurry;

[0009] The remaining liquid phase of the kitchen waste and the solid phase of the kitchen waste are mixed to obtain a mixed slurry of kitchen waste;

[0010] The kitchen waste mixture is subjected to a second saccharification treatment with saccharifying enzymes to obtain saccharified kitchen waste saccharification slurry.

[0011] The saccharified mixed slurry and the saccharified kitchen waste slurry are mixed to obtain fermentation raw materials;

[0012] The fermentation raw materials were subjected to biological fermentation and distillation in sequence to obtain ethanol product.

[0013] Optionally, the first pretreatment of kitchen waste to obtain an oil phase, a liquid phase, and a solid phase of kitchen waste includes:

[0014] The kitchen waste is crushed and pulped to obtain kitchen waste slurry;

[0015] The kitchen waste slurry is degreased to obtain the kitchen waste oil phase, kitchen waste liquid phase and kitchen waste solid phase;

[0016] The kitchen waste slurry contains kitchen waste solid residue with a particle size ≤ 8 mm, the degreasing treatment temperature is ≥ 80℃, and the degreasing treatment time is 0.5h to 4.0h.

[0017] Optionally, the second treatment is a crushing treatment, and the agricultural and forestry waste solid phase contains agricultural and forestry waste solid residue after the crushing treatment, and the particle size of the agricultural and forestry waste solid residue is ≤20mm.

[0018] Optionally, the temperature of the high-temperature treatment is 80℃~180℃, the time of the high-temperature treatment is 10min~360min, and the pH of the high-temperature treatment is adjusted to 1~3.

[0019] Optionally, the temperature of the first saccharification treatment is 50℃~60℃, and the time of the first saccharification treatment is 1h~24h; and / or,

[0020] The temperature of the second saccharification treatment is 50℃~60℃, and the time of the second saccharification treatment is 1h~3h.

[0021] Optionally, the ratio of the cellulase activity U1 to the weight m1 of organic matter in the mixed slurry is (50-1000):1, wherein if the unit of U1 is enzyme activity unit (U), then the unit of m1 is gram (g); and / or,

[0022] The organic matter in the mixed slurry includes cellulose.

[0023] Optionally, the ratio of the enzyme activity U2 of the saccharifying enzyme to the weight m2 of the organic matter in the kitchen waste slurry is (50-1000):1, wherein if the unit of U2 is enzyme activity unit (U), then the unit of m2 is gram (g); and / or,

[0024] The organic matter in the mixed slurry of kitchen waste includes starch.

[0025] Optionally, the weight ratio of the solid phase of the agricultural and forestry waste to the liquid phase of the partial kitchen waste is 1:(0.5-3.0); and / or,

[0026] The weight ratio of the liquid phase of the remaining kitchen waste to the solid phase of the kitchen waste is (0.5-3.0):1.

[0027] Optionally, the solid phase weight of the fermentation feedstock is 10% to 50% of the total weight of the fermentation feedstock.

[0028] Optionally, the microbial strains used in the bio-fermentation treatment include: yeast, wherein the inoculum amount of yeast is 0.05% to 0.10%; and / or,

[0029] The temperature of the bio-fermentation treatment is 25℃~35℃, and the duration of the bio-fermentation treatment is 2d~4d; and / or,

[0030] The temperature at the top of the distillation column is 78℃~94℃.

[0031] The technical solutions provided in this application have the following advantages compared with the prior art:

[0032] This application provides a method for the co-processing of kitchen waste and agricultural and forestry waste. Based on the characteristics of kitchen waste and agricultural and forestry waste containing sugars such as cellulose and starch, the two wastes are first pretreated to fully extract their organic matter. Then, the organic matter from the agricultural and forestry waste undergoes a first saccharification treatment by reacting with cellulase in the acidic environment of the kitchen waste liquid phase. A second saccharification treatment is then performed by reacting the kitchen waste slurry after oil extraction with saccharifying enzymes, converting the organic matter from both wastes into reducing sugars. Most of these reducing sugars are converted into ethanol during subsequent fermentation, thereby improving the resource utilization rate of kitchen waste and agricultural and forestry biomass waste. Furthermore, the produced ethanol can broaden the variety of resource-based products derived from kitchen waste and agricultural and forestry waste. Therefore, using kitchen waste and agricultural and forestry waste as raw materials to produce ethanol can improve the resource utilization rate of these wastes and increase the variety of resource-based products. Attached Figure Description

[0033] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0034] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1A flowchart illustrating a method for the co-processing of kitchen waste and agricultural and forestry waste, provided in an embodiment of this application. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0037] The range descriptions used herein, such as numerical ranges and proportional ranges, include all possible sub-ranges and single numerical values ​​within that range. For example, the range descriptions of "1 to 6" or "1 to 6" cover all sub-ranges (such as 1 to 3, 2 to 5, etc.) and single numbers (such as 1, 2, 3, 4, 5, 6) between 1 and 6. Unless otherwise specified, the terms "including" and "comprise" as used herein mean "including but not limited to"; relational terms such as "first" and "second" are used only to distinguish different entities or operations and do not imply an actual order or relationship; "and / or" indicates that multiple situations can exist individually or simultaneously; expressions such as "at least one," "multiple," and "at least one" refer to any combination of the corresponding objects, including combinations of single or multiple objects. The proportional relationships mentioned herein, such as mass ratios and molar ratios, should be understood as the correspondence between the first and second terms of a proportional formula, according to the order of description. The raw materials, reagents, instruments, and equipment used herein can all be obtained through commercial purchase or prepared using existing methods.

[0038] Figure 1 A flowchart illustrating a method for the co-processing of kitchen waste and agricultural and forestry waste, provided in an embodiment of this application.

[0039] Please see Figure 1 This application provides a method for the co-processing of kitchen waste and agricultural and forestry waste, including:

[0040] S1. The kitchen waste is pretreated to obtain the oil phase, liquid phase and solid phase of the kitchen waste.

[0041] S2. The agricultural and forestry waste undergoes a second pretreatment to obtain the solid phase of the agricultural and forestry waste.

[0042] S3. The solid phase of the agricultural and forestry waste and part of the liquid phase of the kitchen waste are mixed and subjected to high-temperature treatment to obtain a mixed slurry;

[0043] S4. The mixed slurry and cellulase are subjected to a first saccharification treatment to obtain a saccharified mixed slurry;

[0044] S5. Mix the remaining liquid phase of the kitchen waste and the solid phase of the kitchen waste to obtain a mixed slurry of kitchen waste;

[0045] S6. The kitchen waste mixture and saccharifying enzyme are subjected to a second saccharification treatment to obtain saccharified kitchen waste saccharification slurry;

[0046] S7. Mix the saccharified mixed slurry and the saccharified kitchen waste slurry to obtain fermentation raw materials;

[0047] S8. The fermentation raw materials are subjected to biological fermentation and distillation to obtain ethanol product.

[0048] Pretreatment: This can be degreasing treatment for kitchen waste or activation treatment for agricultural and forestry waste. Saccharifying enzyme: This can be β-glucosidase.

[0049] In the above technical solution, high-value components are recovered through three-phase separation and grading of kitchen waste, and a natural acidic medium is obtained. This medium is used to synergistically dissociate the lignocellulose complex structure of agricultural and forestry waste at high temperatures, fully exposing the cellulose. Specific enzymes then perform stepwise saccharification, with cellulase targeting and degrading agricultural and forestry cellulose, and saccharifying enzymes efficiently converting kitchen waste starch into fermentable reducing sugars. After merging the saccharification liquid and optimizing the fermentation substrate characteristics, the mixture is then directionally converted into high-purity ethanol through microbial metabolism and boiling point separation. The entire process utilizes the complementary properties of the two types of waste to drive the reaction, avoiding the addition of external chemicals and achieving a synergistic end-to-end process from raw material dissociation to ethanol conversion.

[0050] In some embodiments, the first pretreatment of kitchen waste to obtain an oil phase, a liquid phase, and a solid phase of kitchen waste includes:

[0051] The kitchen waste is crushed and pulped to obtain kitchen waste slurry;

[0052] The kitchen waste slurry is degreased to obtain the kitchen waste oil phase, kitchen waste liquid phase and kitchen waste solid phase;

[0053] The kitchen waste slurry contains kitchen waste solid residue with a particle size ≤ 8 mm, the degreasing treatment temperature is ≥ 80℃, and the degreasing treatment time is 0.5h to 4.0h.

[0054] There are three methods for crushing and pulping: hydraulic decomposition pulping, sorting and impurity removal pressing pulping, and hot water hydrolysis combined with pressing pulping. First, kitchen waste is crushed and pulped to obtain a kitchen waste slurry with a smaller particle size. Then, the kitchen waste slurry undergoes a three-phase separation and degreasing treatment to separate the oil phase (recoverable grease), liquid phase, and solid phase. A particle size ≤8mm for the kitchen waste solid residue maximizes the specific surface area, significantly improving the grease release rate and enzymatic reaction efficiency in the subsequent degreasing process. For example, the particle size of the kitchen waste solid residue can be 2mm, 4mm, 6mm, 8mm, etc. The degreasing temperature is ≥80℃, and the degreasing time is between 0.5h and 4.0h to ensure thorough degreasing, allowing for complete separation of the grease, liquid, and solid phases of the kitchen waste slurry, thus obtaining a pure degreased kitchen waste slurry. For example, the temperature for degreasing can be 80℃, 82℃, 84℃, 86℃, 88℃, 90℃, 92℃, 94℃, etc.; the time for degreasing can be 0.5h, 1.0h, 1.5h, 2.0h, 2.5h, 3.0h, 3.5h, 4.0h, etc.

[0055] In some embodiments, the second treatment is a crushing treatment, and the agricultural and forestry waste solid phase contains agricultural and forestry waste solid residue after the crushing treatment, and the particle size of the agricultural and forestry waste solid residue is ≤20mm.

[0056] The second processing step is crushing, which transforms large pieces of agricultural and forestry waste into smaller particle sizes of solid waste residue. The particle size of this solid waste residue is ≤20mm, which effectively disrupts the wood fiber bundle structure and simultaneously improves the mass transfer efficiency and enzymatic hydrolysis accessibility during high-temperature processing. For example, the particle size of the solid waste residue can be 5mm, 10mm, 15mm, 20mm, etc.

[0057] In some embodiments, the temperature of the high-temperature treatment is 80°C to 180°C, the time of the high-temperature treatment is 10 min to 360 min, and the pH of the high-temperature treatment is adjusted to 1 to 3.

[0058] Agricultural and forestry waste (solid phase) and some kitchen waste (liquid phase) are mixed and subjected to high-temperature treatment. The acidic environment of the liquid phase, combined with the synergistic thermal effect, dissociates the lignocellulose structure, destroys the encapsulation of cellulose by hemicellulose and lignin, and releases free cellulose to enhance the accessibility of subsequent cellulase. For example, the high-temperature treatment temperature can be 80℃, 100℃, 120℃, 140℃, 160℃, 180℃, etc.; the high-temperature treatment time can be 10 min, 110 min, 210 min, 310 min, etc.; and the high-temperature treatment pH can be 1, 2, 3, etc.

[0059] In some embodiments, the temperature of the first saccharification treatment is 50°C to 60°C, and the time of the first saccharification treatment is 1 hour to 24 hours; and / or,

[0060] The temperature of the second saccharification treatment is 50℃~60℃, and the time of the second saccharification treatment is 1h~3h.

[0061] The temperature of the first saccharification treatment is between 50℃ and 60℃ to maintain the optimal activity temperature of cellulase, maximizing the hydrolysis rate while ensuring enzyme structural stability, thus efficiently degrading cellulose into fermentable sugars. For example, the temperature of the first saccharification treatment can be 50℃, 52℃, 54℃, 56℃, 58℃, 60℃, etc. The duration of the first saccharification treatment is between 1 hour and 24 hours, balancing saccharification rate and economy; short-term treatment rapidly degrades easily convertible components, while long-term treatment breaks down stubborn crystallization zones to increase total sugar yield. For example, the duration of the first saccharification treatment can be 5 hours, 10 hours, 15 hours, 20 hours, etc.

[0062] The temperature of the second saccharification treatment is between 50℃ and 60℃ to maintain the optimal catalytic temperature of the saccharifying enzymes, ensuring efficient hydrolysis of starch and dextrin into glucose and avoiding reaction retardation at low temperatures or enzyme inactivation at high temperatures. For example, the temperature of the second saccharification treatment can be 50℃, 52℃, 54℃, 56℃, 58℃, 60℃, etc. The time of the second saccharification treatment is between 1 hour and 3 hours, matching the easily degradable characteristics of starch in kitchen waste, achieving rapid saccharification and optimized energy consumption. For example, the time of the second saccharification treatment can be 1 hour, 2 hours, 3 hours, etc.

[0063] In some embodiments, the ratio of the cellulase activity U1 to the weight m1 of organic matter in the mixed slurry is (50-1000):1, wherein if the unit of U1 is enzyme activity unit (U), then the unit of m1 is gram (g); and / or,

[0064] The organic matter in the mixed slurry includes cellulose.

[0065] The ratio of cellulase activity U1 to the weight m1 of organic matter in the mixed slurry is (50-1000):1. Precise control of the cellulase dosage achieves an economical balance between the organic matter hydrolysis rate and enzyme cost. Too low a ratio leads to incomplete saccharification, while too high a ratio sharply reduces marginal benefits. For example, the ratio of cellulase activity U1 to the weight m1 of organic matter in the mixed slurry can be 50:1, 100:1, 200:1, 300:1, 400:1, 500:1, 600:1, 700:1, 800:1, 900:1, 1000:1, etc.

[0066] The organic matter in the mixed slurry includes cellulose, which eliminates the interference of hemicellulose and lignin on enzyme activity measurement, ensuring that the unit enzyme activity is targeted to the target substrate and improving the predictability of saccharification efficiency.

[0067] In some embodiments, the ratio of the enzyme activity U2 of the saccharifying enzyme to the weight m2 of the organic matter in the kitchen waste slurry is (50-1000):1, wherein if the unit of U2 is enzyme activity unit (U), then the unit of m2 is gram (g); and / or,

[0068] The organic matter in the mixed slurry of kitchen waste includes starch.

[0069] The ratio of the enzyme activity U2 of the saccharifying enzyme to the weight m2 of organic matter in the mixed kitchen waste slurry is (50-1000):1. This wide-range enzyme activity ratio precisely matches waste materials ranging from low to high starch, ensuring stable saccharification efficiency. For example, the ratio of the enzyme activity U2 of the saccharifying enzyme to the weight m2 of organic matter in the mixed kitchen waste slurry can be 50:1, 100:1, 200:1, 300:1, 400:1, 500:1, 600:1, 700:1, 800:1, 900:1, 1000:1, etc.

[0070] Organic matter in kitchen waste slurry includes starch, which acts as a target substrate for saccharifying enzymes, eliminates the ineffective consumption of enzyme activity by non-target components such as cellulose, and improves the controllability of glucose conversion rate.

[0071] In some embodiments, the weight ratio of the solid phase of the agricultural and forestry waste to the liquid phase of the partial kitchen waste is 1:(0.5-3.0); and / or,

[0072] The weight ratio of the liquid phase of the remaining kitchen waste to the solid phase of the kitchen waste is (0.5-3.0):1.

[0073] The weight ratio of the solid phase of agricultural and forestry waste to the liquid phase of some kitchen waste is 1:(0.5-3.0). This liquid phase ratio controls the rheological properties and mass transfer efficiency of the mixed slurry: a low ratio reduces water replenishment costs, while a high ratio inhibits coking during high-temperature treatment and enhances the dissociation of lignocellulose. For example, the weight ratio of the solid phase of agricultural and forestry waste to the liquid phase of some kitchen waste can be 1:0.5, 1:1.0, 1:1.5, 1:2.0, 1:2.5, 1:3.0, etc.

[0074] The weight ratio of the liquid phase to the solid phase of residual kitchen waste is (0.5–3.0):1, precisely matching the differences in the components of the kitchen waste solid residue: a low ratio is suitable for high-starch solid residue, thereby increasing the saccharification rate of the concentration system; a high ratio optimizes the fluidity of high-fiber solid residue, thereby eliminating the enzyme diffusion barrier. For example, the weight ratio of the liquid phase to the solid phase of residual kitchen waste can be 0.5:1, 1.0:1, 1.5:1, 2.0:1, 2.5:1, 3.0:1, etc.

[0075] In some embodiments, the solid phase weight of the fermentation feedstock is 10% to 50% of the total weight of the fermentation feedstock.

[0076] The solid phase weight of the fermentation feedstock is 10% to 50% of the total weight of the feedstock. This is to precisely control the solid-liquid balance of the fermentation system: a lower limit of 10% ensures the ethanol concentration to avoid a surge in distillation energy consumption, while an upper limit of 50% maintains the fluidity of the slurry to ensure microbial mass transfer efficiency, thus achieving an economical balance between fermentation rate and product yield. For example, the solid phase weight of the fermentation feedstock can be 10%, 20%, 30%, 40%, 50% of the total weight of the feedstock, etc.

[0077] In some embodiments, the microbial strains used in the bio-fermentation treatment include: yeast, wherein the inoculum amount of the yeast is 0.05% to 0.10%; and / or,

[0078] The temperature of the bio-fermentation treatment is 25℃~35℃, and the duration of the bio-fermentation treatment is 2d~4d; and / or,

[0079] The temperature at the top of the distillation column is 78℃~94℃.

[0080] The bio-fermentation process is carried out in a fermenter. The microbial strain used in the bio-fermentation process includes yeast, with an inoculum size between 0.05% and 0.10%. Rapid fermentation is triggered by a critical minimum inoculum size, while the upper limit is controlled to avoid excessive substrate consumption due to excessive cell proliferation, thus simultaneously optimizing ethanol conversion efficiency and the economic viability of the microbial strain. For example, the yeast inoculum size can be 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, etc.

[0081] The bio-fermentation process is carried out at temperatures between 25℃ and 35℃, and for periods between 2 and 4 days. By adjusting the temperature to suit the physiological activity of yeast and controlling the fermentation cycle to match the substrate degradation kinetics, the ethanol conversion efficiency is synergistically optimized while suppressing the generation of byproducts, achieving efficient and targeted conversion of waste sugars into ethanol. For example, the bio-fermentation temperature can be 25℃, 30℃, or 35℃, and the fermentation time can be 2 days, 3 days, or 4 days.

[0082] The distillation column top temperature is maintained between 78℃ and 94℃, precisely controlling the separation window of the azeotropic system to maximize ethanol vaporization purity and suppress the distillation of high-boiling-point impurities. For example, the distillation column top temperature can be 78℃, 80℃, 82℃, 84℃, 86℃, 88℃, 90℃, 92℃, 94℃, etc.

[0083] The present application is further illustrated below with reference to specific embodiments. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to national / industry standards; if there is no corresponding national / industry standard, they are performed according to general international standards, conventional conditions, or conditions recommended by the manufacturer.

[0084] Example 1

[0085] Kitchen waste is crushed and pulped to obtain kitchen waste slurry. The kitchen waste slurry is then degreased to obtain kitchen waste oil phase, kitchen waste liquid phase and kitchen waste solid phase. The particle size of the kitchen waste solid residue is 8 mm, the degreasing temperature is 80℃ and the degreasing time is 1 hour.

[0086] Agricultural and forestry waste is crushed to obtain agricultural and forestry waste solid phase; wherein the particle size of the agricultural and forestry waste solid residue is 15mm.

[0087] The solid phase of agricultural and forestry waste and the liquid phase of some kitchen waste were mixed, with a weight ratio of 1:1. The mixture was then subjected to high-temperature treatment at 180℃ for 1 hour, and the pH was adjusted to 1.5 to obtain a mixed slurry.

[0088] The mixed slurry and cellulase were subjected to a first saccharification treatment, wherein the ratio of the enzyme activity U1 of cellulase to the weight m1 of organic matter in the mixed slurry was 50:1; the temperature of the first saccharification treatment was 55℃ and the time of the first saccharification treatment was 6h, to obtain a saccharified mixed slurry.

[0089] The liquid phase and solid phase of the remaining kitchen waste are mixed, wherein the weight ratio of the liquid phase to the solid phase of the remaining kitchen waste is 1:1, to obtain a mixed slurry of kitchen waste.

[0090] The kitchen waste mixture was subjected to a second saccharification treatment with a saccharifying enzyme, wherein the ratio of the enzyme activity U2 of the saccharifying enzyme to the weight m2 of the organic matter in the kitchen waste mixture was 50:1; the temperature of the second saccharification treatment was 55℃ and the time of the second saccharification treatment was 30 min, to obtain saccharified kitchen waste mixture.

[0091] The saccharified mixed slurry and the saccharified kitchen waste slurry are mixed to obtain the fermentation raw material; wherein, the solid phase weight of the fermentation raw material is 40% of the total weight of the fermentation raw material.

[0092] The fermentation raw materials were subjected to biological fermentation and distillation in sequence. The yeast strain used in the biological fermentation was 0.05%; the biological fermentation temperature was 28℃ and the fermentation time was 3 days; the temperature at the top of the distillation column was 78℃, and ethanol product was obtained.

[0093] Example 2

[0094] Kitchen waste is crushed and pulped to obtain kitchen waste slurry. The kitchen waste slurry is then degreased to obtain kitchen waste oil phase, kitchen waste liquid phase and kitchen waste solid phase. The particle size of the kitchen waste solid residue is 8 mm, the degreasing temperature is 80℃ and the degreasing time is 1 hour.

[0095] Agricultural and forestry waste is crushed to obtain agricultural and forestry waste solid phase; wherein the particle size of the agricultural and forestry waste solid residue is 15mm.

[0096] The solid phase of agricultural and forestry waste and the liquid phase of some kitchen waste were mixed, with a weight ratio of 1:1. The mixture was then subjected to high-temperature treatment at 180℃ for 1 hour, and the pH was adjusted to 1.5 to obtain a mixed slurry.

[0097] The mixed slurry and cellulase were subjected to a first saccharification treatment, wherein the ratio of the enzyme activity U1 of cellulase to the weight m1 of organic matter in the mixed slurry was 200:1; the temperature of the first saccharification treatment was 55℃ and the time of the first saccharification treatment was 6h, to obtain a saccharified mixed slurry.

[0098] The liquid phase and solid phase of the remaining kitchen waste are mixed, wherein the weight ratio of the liquid phase to the solid phase of the remaining kitchen waste is 1:1, to obtain a mixed slurry of kitchen waste.

[0099] The mixed slurry of kitchen waste was subjected to a second saccharification treatment with a saccharifying enzyme. The ratio of the enzyme activity U2 of the saccharifying enzyme to the weight m2 of the organic matter in the mixed slurry of kitchen waste was 200:1. The temperature of the second saccharification treatment was 55℃ and the time of the second saccharification treatment was 30 min, resulting in saccharified kitchen waste slurry.

[0100] The saccharified mixed slurry and the saccharified kitchen waste slurry are mixed to obtain the fermentation raw material; wherein, the solid phase weight of the fermentation raw material is 40% of the total weight of the fermentation raw material.

[0101] The fermentation raw materials were subjected to biological fermentation and distillation in sequence. The yeast strain used in the biological fermentation was 0.05%; the biological fermentation temperature was 28℃ and the fermentation time was 3 days; the temperature at the top of the distillation column was 78℃, and ethanol product was obtained.

[0102] Example 3

[0103] Kitchen waste is crushed and pulped to obtain kitchen waste slurry. The kitchen waste slurry is then degreased to obtain kitchen waste oil phase, kitchen waste liquid phase and kitchen waste solid phase. The particle size of the kitchen waste solid residue is 8 mm, the degreasing temperature is 80℃ and the degreasing time is 1 hour.

[0104] Agricultural and forestry waste is crushed to obtain agricultural and forestry waste solid phase; wherein the particle size of the agricultural and forestry waste solid residue is 15mm.

[0105] The solid phase of agricultural and forestry waste and the liquid phase of some kitchen waste were mixed, with a weight ratio of 1:1. The mixture was then subjected to high-temperature treatment at 120℃ for 2 hours, and the pH was adjusted to 3 to obtain a mixed slurry.

[0106] The mixed slurry and cellulase were subjected to a first saccharification treatment, wherein the ratio of the enzyme activity U1 of cellulase to the weight m1 of organic matter in the mixed slurry was 50:1; the temperature of the first saccharification treatment was 55℃ and the time of the first saccharification treatment was 6h, to obtain a saccharified mixed slurry.

[0107] The liquid phase and solid phase of the remaining kitchen waste are mixed, wherein the weight ratio of the liquid phase to the solid phase of the remaining kitchen waste is 1:1, to obtain a mixed slurry of kitchen waste.

[0108] The kitchen waste mixture was subjected to a second saccharification treatment with a saccharifying enzyme, wherein the ratio of the enzyme activity U2 of the saccharifying enzyme to the weight m2 of the organic matter in the kitchen waste mixture was 50:1; the temperature of the second saccharification treatment was 55℃ and the time of the second saccharification treatment was 30 min, to obtain saccharified kitchen waste mixture.

[0109] The saccharified mixed slurry and the saccharified kitchen waste slurry are mixed to obtain the fermentation raw material; wherein, the solid phase weight of the fermentation raw material is 40% of the total weight of the fermentation raw material.

[0110] The fermentation raw materials were subjected to biological fermentation and distillation in sequence. The yeast strain used in the biological fermentation was 0.05%; the biological fermentation temperature was 28℃ and the fermentation time was 3 days; the temperature at the top of the distillation column was 78℃, and ethanol product was obtained.

[0111] Example 4

[0112] Kitchen waste is crushed and pulped to obtain kitchen waste slurry. The kitchen waste slurry is then degreased to obtain kitchen waste oil phase, kitchen waste liquid phase and kitchen waste solid phase. The particle size of the kitchen waste solid residue is 8 mm, the degreasing temperature is 80℃ and the degreasing time is 1 hour.

[0113] Agricultural and forestry waste is crushed to obtain agricultural and forestry waste solid phase; wherein the particle size of the agricultural and forestry waste solid residue is 15mm.

[0114] The solid phase of agricultural and forestry waste and the liquid phase of some kitchen waste were mixed, with a weight ratio of 1:1. The mixture was then subjected to high-temperature treatment at 180℃ for 1 hour, and the pH was adjusted to 1.5 to obtain a mixed slurry.

[0115] The mixed slurry and cellulase were subjected to a first saccharification treatment, wherein the ratio of the enzyme activity U1 of cellulase to the weight m1 of organic matter in the mixed slurry was 50:1; the temperature of the first saccharification treatment was 55℃ and the time of the first saccharification treatment was 6h, to obtain a saccharified mixed slurry.

[0116] The liquid phase and solid phase of the remaining kitchen waste are mixed, wherein the weight ratio of the liquid phase to the solid phase of the remaining kitchen waste is 1:1, to obtain a mixed slurry of kitchen waste.

[0117] The kitchen waste mixture was subjected to a second saccharification treatment with a saccharifying enzyme, wherein the ratio of the enzyme activity U2 of the saccharifying enzyme to the weight m2 of the organic matter in the kitchen waste mixture was 50:1; the temperature of the second saccharification treatment was 55℃ and the time of the second saccharification treatment was 30 min, to obtain saccharified kitchen waste mixture.

[0118] The saccharified mixed slurry and the saccharified kitchen waste slurry are mixed to obtain the fermentation raw material; wherein, the solid phase weight of the fermentation raw material is 40% of the total weight of the fermentation raw material.

[0119] The fermentation raw materials were subjected to biological fermentation and distillation in sequence. The yeast strain used in the biological fermentation was 0.05%; the biological fermentation temperature was 33℃ and the fermentation time was 4 days; the temperature at the top of the distillation column was 78℃, and ethanol product was obtained.

[0120] Example 5

[0121] Kitchen waste is crushed and pulped to obtain kitchen waste slurry. The kitchen waste slurry is then degreased to obtain kitchen waste oil phase, kitchen waste liquid phase and kitchen waste solid phase. The particle size of the kitchen waste solid residue is 8 mm, the degreasing temperature is 80℃ and the degreasing time is 1 hour.

[0122] Agricultural and forestry waste is crushed to obtain agricultural and forestry waste solid phase; wherein the particle size of the agricultural and forestry waste solid residue is 15mm.

[0123] The solid phase of agricultural and forestry waste and the liquid phase of some kitchen waste were mixed, with a weight ratio of 1:3. The mixture was then subjected to high-temperature treatment at 180℃ for 1 hour, and the pH was adjusted to 1.5 to obtain a mixed slurry.

[0124] The mixed slurry and cellulase were subjected to a first saccharification treatment, wherein the ratio of the enzyme activity U1 of cellulase to the weight m1 of organic matter in the mixed slurry was 50:1; the temperature of the first saccharification treatment was 55℃ and the time of the first saccharification treatment was 6h, to obtain a saccharified mixed slurry.

[0125] The liquid phase and solid phase of the remaining kitchen waste are mixed, wherein the weight ratio of the liquid phase to the solid phase of the remaining kitchen waste is 3:1, to obtain a mixed slurry of kitchen waste.

[0126] The kitchen waste mixture was subjected to a second saccharification treatment with a saccharifying enzyme, wherein the ratio of the enzyme activity U2 of the saccharifying enzyme to the weight m2 of the organic matter in the kitchen waste mixture was 50:1; the temperature of the second saccharification treatment was 55℃ and the time of the second saccharification treatment was 30 min, to obtain saccharified kitchen waste mixture.

[0127] The saccharified mixed slurry and the saccharified kitchen waste slurry are mixed to obtain the fermentation raw material; wherein, the solid phase weight of the fermentation raw material is 10% of the total weight of the fermentation raw material.

[0128] The fermentation raw materials were subjected to biological fermentation and distillation in sequence. The yeast strain used in the biological fermentation was 0.05%; the biological fermentation temperature was 28℃ and the fermentation time was 3 days; the temperature at the top of the distillation column was 78℃, and ethanol product was obtained.

[0129] Comparative Example 1

[0130] Kitchen waste is crushed and pulped to obtain kitchen waste slurry. The kitchen waste slurry is then degreased to obtain kitchen waste oil phase, kitchen waste liquid phase and kitchen waste solid phase. The particle size of the kitchen waste solid residue is 8 mm, the degreasing temperature is 80℃ and the degreasing time is 1 hour.

[0131] The liquid phase and solid phase of kitchen waste are mixed, wherein the weight ratio of the liquid phase to the solid phase of kitchen waste is 1:1, to obtain a mixed slurry of kitchen waste.

[0132] The mixed slurry of kitchen waste was subjected to saccharification treatment with a saccharifying enzyme. The ratio of the enzyme activity U2 of the saccharifying enzyme to the weight m2 of the organic matter in the mixed slurry of kitchen waste was 50:1. The saccharification treatment temperature was 55℃ and the saccharification time was 30 min, resulting in saccharified kitchen waste slurry.

[0133] The saccharified mixed slurry is used as the fermentation raw material; wherein, the solid phase weight of the fermentation raw material is 20% of the total weight of the fermentation raw material.

[0134] The fermentation raw materials were subjected to biological fermentation and distillation in sequence. The yeast strain used in the biological fermentation was 0.05%; the biological fermentation temperature was 28℃ and the fermentation time was 3 days; the temperature at the top of the distillation column was 78℃, and ethanol product was obtained.

[0135] Comparative Example 2

[0136] Kitchen waste is crushed and pulped to obtain kitchen waste slurry. The kitchen waste slurry is then degreased to obtain kitchen waste oil phase, kitchen waste liquid phase and kitchen waste solid phase. The particle size of the kitchen waste solid residue is 8 mm, the degreasing temperature is 80℃ and the degreasing time is 1 hour.

[0137] Agricultural and forestry waste is crushed to obtain agricultural and forestry waste solid phase; wherein the particle size of the agricultural and forestry waste solid residue is 15mm.

[0138] The solid phase of agricultural and forestry waste and the liquid phase of some kitchen waste were mixed, with a weight ratio of 1:1. The mixture was then subjected to high-temperature treatment at 180℃ for 1 hour, and the pH was adjusted to 1.5 to obtain a mixed slurry.

[0139] The liquid phase and solid phase of the remaining kitchen waste are mixed, wherein the weight ratio of the liquid phase to the solid phase of the remaining kitchen waste is 1:1, to obtain a mixed slurry of kitchen waste.

[0140] The mixed slurry and kitchen waste slurry are mixed to obtain the fermentation raw material; wherein, the solid phase weight of the fermentation raw material is 40% of the total weight of the fermentation raw material.

[0141] The fermentation raw materials were subjected to biological fermentation and distillation in sequence. The yeast strain used in the biological fermentation was 0.05%; the biological fermentation temperature was 28℃ and the fermentation time was 3 days; the temperature at the top of the distillation column was 78℃, and ethanol product was obtained.

[0142] Comparative Example 3

[0143] Kitchen waste is crushed and pulped to obtain kitchen waste slurry. The kitchen waste slurry is then degreased to obtain kitchen waste oil phase, kitchen waste liquid phase and kitchen waste solid phase. The particle size of the kitchen waste solid residue is 8 mm, the degreasing temperature is 80℃ and the degreasing time is 1 hour.

[0144] Agricultural and forestry waste is crushed to obtain agricultural and forestry waste solid phase; wherein the particle size of the agricultural and forestry waste solid residue is 15mm.

[0145] The solid phase of agricultural and forestry waste and the liquid phase of some kitchen waste were mixed, with a weight ratio of 1:1. The mixture was then subjected to high-temperature treatment at 180℃ for 1 hour, and the pH was adjusted to 1.5 to obtain a mixed slurry.

[0146] The mixed slurry and cellulase were subjected to a first saccharification treatment, wherein the ratio of the enzyme activity U1 of cellulase to the weight m1 of organic matter in the mixed slurry was 50:1; the temperature of the first saccharification treatment was 55℃ and the time of the first saccharification treatment was 6h, to obtain a saccharified mixed slurry.

[0147] The liquid phase and solid phase of the remaining kitchen waste are mixed, wherein the weight ratio of the liquid phase to the solid phase of the remaining kitchen waste is 1:1, to obtain a mixed slurry of kitchen waste.

[0148] The kitchen waste mixture was subjected to a second saccharification treatment with a saccharifying enzyme, wherein the ratio of the enzyme activity U2 of the saccharifying enzyme to the weight m2 of the organic matter in the kitchen waste mixture was 50:1; the temperature of the second saccharification treatment was 55℃ and the time of the second saccharification treatment was 30 min, to obtain saccharified kitchen waste mixture.

[0149] The saccharified mixed slurry and the saccharified kitchen waste slurry are mixed to obtain the fermentation raw material; wherein, the solid phase weight of the fermentation raw material is 40% of the total weight of the fermentation raw material.

[0150] The fermentation raw materials were subjected to biological fermentation and distillation in sequence. The yeast strain used in the biological fermentation was 0.05%; the biological fermentation temperature was 20℃ and the fermentation time was 1 day; the temperature at the top of the distillation column was 78℃, and ethanol product was obtained.

[0151] Comparative Example 4

[0152] Kitchen waste is crushed and pulped to obtain kitchen waste slurry. The kitchen waste slurry is then degreased to obtain kitchen waste oil phase, kitchen waste liquid phase and kitchen waste solid phase. The particle size of the kitchen waste solid residue is 8 mm, the degreasing temperature is 80℃ and the degreasing time is 1 hour.

[0153] Agricultural and forestry waste is crushed to obtain agricultural and forestry waste solid phase; wherein the particle size of the agricultural and forestry waste solid residue is 15mm.

[0154] Agricultural and forestry waste solid phase and cellulase were subjected to a first saccharification treatment, wherein the ratio of the enzyme activity U1 of cellulase to the weight m1 of organic matter in the mixed slurry was 50:1; the temperature of the first saccharification treatment was 55℃ and the time of the first saccharification treatment was 6h, to obtain saccharified agricultural and forestry waste slurry.

[0155] The liquid phase and solid phase of kitchen waste are mixed, wherein the weight ratio of the liquid phase to the solid phase of kitchen waste is 1:1, to obtain a mixed slurry of kitchen waste.

[0156] The kitchen waste mixture was subjected to a second saccharification treatment with a saccharifying enzyme, wherein the ratio of the enzyme activity U2 of the saccharifying enzyme to the weight m2 of the organic matter in the kitchen waste mixture was 50:1; the temperature of the second saccharification treatment was 55℃ and the time of the second saccharification treatment was 30 min, to obtain saccharified kitchen waste mixture.

[0157] Saccharified agricultural and forestry waste slurry and saccharified kitchen waste slurry are mixed to obtain fermentation raw materials; wherein, the solid phase weight of the fermentation raw materials is 40% of the total weight of the fermentation raw materials.

[0158] The fermentation raw materials were subjected to biological fermentation and distillation in sequence. The yeast strain used in the biological fermentation was 0.05%; the biological fermentation temperature was 28℃ and the fermentation time was 3 days; the temperature at the top of the distillation column was 78℃, and ethanol product was obtained.

[0159] Results data: The concentrations and yields of the ethanol products from Examples 1 to 5 and Comparative Examples 1 to 4 are shown in Table 1.

[0160] Experimental methods for obtaining effect data:

[0161] 1. Determination of ethanol product concentration: The "General Analytical Methods for Alcohol" (GB / T394.2-2008) was adopted.

[0162] 2. Calculation of ethanol yield: Ethanol yield = weight of ethanol product / weight of kitchen waste and agricultural and forestry waste materials.

[0163] Table 1

[0164]

[0165]

[0166] The above effect data table provides a clear comparison of the differences between various embodiments and comparative examples. The following conclusions can be drawn:

[0167] As can be seen from Examples 1 to 5, the preparation method of this application can produce ethanol products by using kitchen waste and agricultural and forestry waste as raw materials through saccharification and bio-fermentation. The concentration of the ethanol product reaches more than 95%, and the yield of ethanol reaches 5% or more. This shows that the method can effectively improve the resource utilization rate of kitchen waste and agricultural and forestry waste and the variety of resource products.

[0168] As can be seen from Comparative Examples 1 to 4, without using the preparation method of the embodiments of this application, the concentration of the ethanol product reaches 95%, but the yield of ethanol is low. These indicators are not as good as those of the embodiments, indicating that the above problems cannot be effectively solved without using the method of the present invention.

[0169] One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages:

[0170] Co-processing of kitchen waste and agricultural and forestry waste: Utilizing the natural acidity of kitchen waste to dissociate the lignocellulose structure during high-temperature treatment, combined with two-stage directional saccharification by cellulase and saccharifying enzyme, the conversion rate of reducing sugars is increased while the yield of ethanol is also increased. The co-processing of the two maximizes the resource utilization of kitchen waste and agricultural and forestry waste.

[0171] Conversion of high-value products: This method transforms kitchen waste and agricultural and forestry waste into ethanol products with practical application value.

[0172] High economic benefits: Compared to traditional treatment methods that are limited to simple recycling or landfill, this method helps alleviate resource shortages and promotes the development of a circular economy.

[0173] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. 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 this application. Therefore, this application 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 claimed in this application.

Claims

1. A method for the co-processing of kitchen waste and agricultural and forestry waste, characterized in that, The method includes: The kitchen waste is crushed and pulped to obtain kitchen waste slurry; The kitchen waste slurry is degreased to obtain the kitchen waste oil phase, kitchen waste liquid phase and kitchen waste solid phase. The kitchen waste slurry contains kitchen waste solid residue with a particle size ≤8mm. The degreasing temperature is ≥80℃ and the degreasing time is 0.5h~4.0h. Agricultural and forestry waste is crushed to obtain the solid phase of agricultural and forestry waste; The solid phase of the agricultural and forestry waste and a portion of the liquid phase of the kitchen waste are mixed and subjected to high-temperature treatment to obtain a mixed slurry. The high-temperature treatment temperature is 80℃~180℃, the high-temperature treatment time is 10min~360min, the pH of the high-temperature treatment is adjusted to 1~3, and the weight ratio of the solid phase of the agricultural and forestry waste to the liquid phase of the kitchen waste is 1:(0.5~3.0). The mixed slurry and cellulase are subjected to a first saccharification treatment to obtain a saccharified mixed slurry. The temperature of the first saccharification treatment is 50℃~60℃, and the time of the first saccharification treatment is 1h~24h. The ratio of the enzyme activity U1 of the cellulase to the weight m1 of the organic matter in the mixed slurry is (50~1000):

1. Wherein, if the unit of U1 is enzyme activity unit (U), then the unit of m1 is gram (g). The remaining liquid phase of the kitchen waste and the solid phase of the kitchen waste are mixed to obtain a mixed slurry of kitchen waste, wherein the weight ratio of the remaining liquid phase of the kitchen waste to the solid phase of the kitchen waste is (0.5~3.0):1; The mixed slurry of kitchen waste is subjected to a second saccharification treatment with a saccharifying enzyme to obtain a saccharified kitchen waste slurry. The temperature of the second saccharification treatment is 50℃~60℃, and the time of the second saccharification treatment is 1h~3h. The ratio of the enzyme activity U2 of the saccharifying enzyme to the weight m2 of the organic matter in the mixed slurry of kitchen waste is (50~1000):

1. Wherein, if the unit of U2 is enzyme activity unit (U), then the unit of m2 is gram (g). The saccharified mixed slurry and the saccharified kitchen waste slurry are mixed to obtain fermentation raw materials; The fermentation raw materials are subjected to biological fermentation and distillation in sequence to obtain ethanol products. The solid phase weight of the fermentation raw materials is 10% to 50% of the total weight of the fermentation raw materials.

2. The method according to claim 1, characterized in that, The solid phase of the agricultural and forestry waste, after being crushed, contains solid residue of agricultural and forestry waste, and the particle size of the solid residue of agricultural and forestry waste is ≤20mm.

3. The method according to claim 1, characterized in that, The organic matter in the mixed slurry includes cellulose.

4. The method according to claim 1, characterized in that, The organic matter in the mixed slurry of kitchen waste includes starch.

5. The method according to claim 1, characterized in that, The microbial strains used in the bio-fermentation treatment include: yeast, wherein the inoculum amount of yeast is 0.05%~0.10%; and / or, The temperature of the bio-fermentation treatment is 25℃~35℃, and the duration of the bio-fermentation treatment is 2d~4d; and / or, The temperature at the top of the distillation column is 78℃~94℃.

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