Integrated method based on vinasse high-value recovery, photosynthetic bacteria culture and biochar preparation

Abstract

The invention discloses an integrated method based on vinasse high-value recovery, photosynthetic bacteria culture and biochar preparation, which comprises the following steps: S1, extracting high-value substances in vinasse through ultrasonic-assisted enzymolysis, and then carrying out solid-liquid separation to realize material distribution; s2, performing nutrient purification and separation on the liquid-phase product obtained in the S1; s3, carrying out self-fermentation treatment on the solid-phase residues obtained in the S1, and then carrying out solid-liquid separation again; s4, culturing by taking the liquid phase obtained in S3 as a culture medium of photosynthetic bacteria; and S5, preparing the solid phase obtained in S3 into the biochar through a pyrolysis process.

Description

Technical Field

[0001] The present invention relates to the field of vinasse recovery, and in particular to an integrated method based on high-value vinasse recovery, photosynthetic bacteria cultivation and biochar preparation. Background Art

[0002] Amidst the rapid growth of the global brewing industry, distiller's grains disposal has become a core challenge hindering the industry's sustainable development. Globally, according to statistics from the Food and Agriculture Organization of the United Nations (FAO), global production of alcoholic beverages reached 193 million tons in 2022, with distiller's grains exceeding 350 million tons. my country, the world's largest producer of baijiu (white spirits), already produces over 40 million tons of distiller's grains annually.

[0003] This type of distiller's grains by-product has remarkable characteristics. Its moisture content is as high as 60%-70%, and its organic matter load is also extremely high. The chemical oxygen demand (COD) reaches 5×10 4 -8×10 4 If the waste is disposed of using traditional landfill methods, not only will the leachate pollute groundwater, with ammonia nitrogen concentration exceeding 200 mg / L, but the methane emissions generated during its decay process can reach 12.5 kgCO2-eq / t, which puts enormous pressure on the environment.

[0004] Although feed utilization can absorb about 30% of the distiller's grains, the digestibility of livestock and poultry is generally less than 40% due to the anti-nutritional factors such as lignin (15%-22% of dry weight) and polyphenol polymer tannin (2%-5% of dry weight) contained in the distiller's grains. The actual resource conversion efficiency needs to be improved urgently.

[0005] A thorough analysis of current mainstream distiller's grains processing technologies reveals significant technical and economic bottlenecks. While physical drying can produce feed materials with moisture contents below 10%, hot air drying consumes up to 850kcal / kgH₂O, significantly increasing processing costs. Chemical acid-base pretreatment, while capable of degrading cellulose, also results in 18%-35% protein denaturation losses. Single-strain fermentation processes, such as ethanol-producing yeast fermentation, can achieve sugar conversion, but over 40% of the lignocellulosic components remain in the fermentation residue, preventing full utilization of the material.

[0006] More importantly, most existing research focuses on the development of single products, such as feed protein fortification or biofuel preparation, and lacks systematic research on the synergistic transformation of multiple components of distiller's grains. This has directly led to the long-term stagnation of resource utilization at the level of 45%-60%.

[0007] In recent years, the circular economy model has provided new insights for the high-value utilization of distiller's grains. Its processing pipeline generally follows the steps of high-value extraction, secondary utilization, energy conversion, and final disposal. However, existing circular economy models still suffer from numerous shortcomings in practical application. For one thing, they typically focus on utilizing a single or a few components of spent grains, failing to fully transform and utilize the entire spectrum of their constituents. Furthermore, the resulting products, such as feed, biogas, and organic fertilizer, experience significant price fluctuations and generally exhibit low added value, significantly limiting potential for economic improvement. Furthermore, environmental benefits also present challenges. Feed production carries the risk of mycotoxin accumulation. Anaerobic fermentation produces large volumes of digestate and liquid, which are difficult to handle and can easily lead to nitrogen and phosphorus pollution. Furthermore, composting produces odors (such as ammonia and hydrogen sulfide) and leachate.

[0008] In summary, the existing technical system has a series of defects such as insufficient component utilization, low product added value, and high environmental risks. There is an urgent need for a new method that can realize the conversion of all components of distiller's grains, improve resource utilization and product added value, and reduce environmental risks. Summary of the Invention

[0009] The present invention aims to provide an integrated method based on high-value recovery of vinasse, cultivation of photosynthetic bacteria and preparation of biochar to solve the problem of high vinasse production and difficult treatment and disposal. The method has simple process, mild conditions and no secondary pollution.

[0010] In order to achieve the above objectives, this application provides the following technical solutions: An integrated method based on high-value recovery of distiller's grains, cultivation of photosynthetic bacteria and preparation of biochar, comprising the following steps: S1, extracting high-value substances from distiller's grains through ultrasound-assisted enzymatic hydrolysis, followed by solid-liquid separation to achieve material diversion; S2, purifying and separating nutrients from the liquid product obtained in S1; S3, subjecting the solid residue obtained in S1 to self-fermentation treatment, followed by solid-liquid separation again; S4, culturing the liquid phase obtained in S3 as a culture medium for photosynthetic bacteria; S5, preparing biochar from the solid phase obtained in S3 through a pyrolysis process.

[0011] Working principle and beneficial effects of the present invention: Compared with traditional distiller's grains treatment and disposal, this method does not have the final discharge of unused distiller's grains residue, achieves more than 85% distiller's grains resource utilization, and the final products are nutrients (polysaccharides, peptides, phenols), photosynthetic bacteria and biochar.

[0012] Compared with existing circular economy models, this approach offers 1) more thorough resource utilization and deeper value exploration. Existing models typically focus on utilizing a single or a few components of waste slag, while this approach offers the advantage of "full component conversion." 2) Significantly improved economic benefits. Existing models suffer from significant market price fluctuations and generally low added value for products such as feed, biogas, and organic fertilizer, limiting potential for further economic improvement. The bioactive substances (such as specific proteins, functional polysaccharides, and phenolic extracts) and photosynthetic bacterial products (such as high-purity coenzyme Q10 and carotenoids) extracted from waste slag using this approach have a market value far higher than traditional feed or fertilizer. Biochar also has promising market prospects as an environmental remediation material and soil conditioner. 3) Better environmental benefits. Existing models for feed production may pose a risk of mycotoxin accumulation; anaerobic digestion produces large volumes of digestate and liquid, making it difficult to handle and prone to nitrogen and phosphorus pollution; and the composting process generates odors (such as ammonia and hydrogen sulfide) and leachate. The solid residue of this method is almost completely converted into stable and valuable biochar, achieving complete solid waste resource utilization and greatly reducing the risk of landfill occupation and environmental pollution.

[0013] The present method utilizes fermentation broth to cultivate photosynthetic bacteria, with the following features: 1) The residual liquid after extracting high-value substances from winemaking waste is rich in unutilized soluble organic matter, phosphorus, potassium, trace elements, and vitamins, which are ideal nutrient sources for the growth and reproduction of photosynthetic bacteria; 2) Nutrients in the residual liquid are mostly present in small molecules or in a soluble state (partly due to pretreatment in the early extraction process), making them more easily absorbed and utilized by photosynthetic bacteria, thereby promoting their rapid growth and high-density culture; 3) The remaining nutrients in the residual liquid are "secondarily extracted" by photosynthetic bacteria and converted into high-value bacterial products, maximizing the overall utilization rate of the waste grain resources; 4) High-value compounds such as coenzyme Q10 (CoQ10), astaxanthin, carotenoids, B vitamins, and 5-ALA (5-aminolevulinic acid) can be accumulated and can be used in health products, cosmetics, and pharmaceutical raw materials.

[0014] Through the synergistic effect of each step, efficient resource utilization and high value-added product transformation are achieved, solving the problems of insufficient component utilization and low product value-added in the existing technology. (1) Ultrasonic-assisted enzymatic extraction can extract phenolic acids, which can be used in food wrap or cosmetic anti-aging products; alkaline protease hydrolysis of lees protein can obtain ACE inhibitory peptides and antioxidant peptides, which can be used in blood pressure capsules and functional beverages. (2) After the nutrients are extracted, the lees are subjected to self-fermentation treatment, the supernatant and solid residue are separated, and the carbon and nitrogen in the fermentation liquid are used to cultivate photosynthetic bacteria, achieving resource transfer. (3) The prepared biochar can be used for soil improvement, adsorption of heavy metals, etc. (4) Compared with traditional lees treatment and disposal, the overall cost of this method is reduced by 30%, and the resource utilization rate is increased to more than 85%.

[0015] Optimized, the ultrasonic time of the ultrasonic-assisted enzymatic hydrolysis in S1 is 30 min, the ultrasonic frequency is 20-40 kHz, and the enzymes used are a combination of cellulase and alkaline protease, with the ratio of the two being 1:1.

[0016] Optimized, during the self-fermentation treatment in S3, the initial moisture content of the lees is adjusted to 55%-65%, and fermented in an anaerobic environment at room temperature for 3-5 days.

[0017] Optimally, the photosynthetic bacteria culture temperature in S4 is 30-35° C., the pH is 7.0-7.5, and continuous illumination is performed at a light intensity of 2000 Lux in an anaerobic environment.

[0018] Optimized conditions for the pyrolysis process in S5 are: heating in a tube furnace at 500-600° C. for 1-2 h while continuously purging with nitrogen to maintain an oxygen-free environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a technical flow chart for the full-component conversion of brewing waste grains based on high-value material recovery, photosynthetic bacteria cultivation, and biochar preparation. Figure 2 Schematic diagram of ultrasound-assisted enzymatic hydrolysis reactor; Figure 3 Schematic diagram of biochar preparation; Figure 4 Schematic diagram of the self-fermentation of liquor lees after the extraction of high-value substances; Figure 5 Schematic diagram of photosynthetic bacteria culture. DETAILED DESCRIPTION

[0020] The following is further described in detail through specific implementation methods: Example 1 like Figure 1 As shown, high-value substances (polysaccharides, peptides, phenols) in the lees are first extracted through ultrasound-assisted enzymatic hydrolysis, and then solid-liquid separation is used to achieve material diversion - the liquid phase product is used to purify and separate nutrients, and the solid phase residue is self-fermented, and then the solid-liquid separation is performed again. The liquid phase is a high-COD fermentation liquid, which serves as a culture medium for photosynthetic bacteria, and the solid phase is prepared as biochar through a pyrolysis process.

[0021] Example 2 Ultrasonic-assisted enzyme extraction (UAEE) of high-value substances enhances enzymatic hydrolysis efficiency through ultrasonic cavitation effect, shortens extraction time and improves yield, including: ultrasonic equipment, ultrasonic treatment conditions: ultrasonic time 30 minutes, ultrasonic frequency 20-40kHz; enzyme selection: cellulase + alkaline protease, ratio of 1:1.

[0022] Example 3 Biochar production involves fermenting lees from which nutrients have been extracted, performing solid-liquid separation, and then producing biochar from the solid phase, achieving efficient resource utilization. Pyrolysis process conditions: heating in a tubular furnace at 500-600°C for 1-2 hours while continuously purging with nitrogen to maintain an oxygen-free environment.

[0023] Example 4 After extracting high-value substances, the liquor lees are allowed to ferment spontaneously. The initial moisture content of the lees is adjusted to 55%-65%, and the fermentation is carried out in an anaerobic environment at room temperature for 3-5 days. After fermentation, solid-liquid separation is performed.

[0024] Example 5 Cultivate photosynthetic bacteria (PSB) using fermentation broth to produce large quantities of cells. Temperature: 30-35°C, pH 7.0-7.5, anaerobic environment. Light intensity: 2000 Lux continuous light. The resulting PSB biomass has a protein content of ≥50% and can be processed into aquatic feed or food additives.

[0025] The above is only an embodiment of the present invention, and the common knowledge such as the specific structure and characteristics of the scheme is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several variations and improvements can be made, which should also be regarded as the scope of protection of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. An integrated method based on high-value recovery of lees, cultivation of photosynthetic bacteria and preparation of biochar, characterized in that: The method comprises the following steps: S1, extracting high-value substances from wine dregs through ultrasonic-assisted enzymatic hydrolysis, and then performing solid-liquid separation to realize material diversion; S2, purifying and separating nutrients from the liquid product obtained in S1; S3, subjecting the solid residue obtained in S1 to self-fermentation treatment, and then performing solid-liquid separation again; S4, culturing the liquid phase obtained in S3 as a culture medium for photosynthetic bacteria; and S5, preparing biochar from the solid phase obtained in S3 through a pyrolysis process.

2. The integrated method based on high-value recovery of lees, cultivation of photosynthetic bacteria and preparation of biochar according to claim 1, characterized in that: The ultrasonic time of the ultrasonic-assisted enzymatic hydrolysis in S1 is 30 min, the ultrasonic frequency is 20-40 kHz, and the enzymes used are a combination of cellulase and alkaline protease in a ratio of 1:

1.

3. The integrated method based on high-value recovery of lees, cultivation of photosynthetic bacteria and preparation of biochar according to claim 1, characterized in that: During the self-fermentation treatment in S3, the initial moisture content of the vinasse is adjusted to 55%-65%, and fermented in an anaerobic environment at room temperature for 3-5 days.

4. The integrated method based on high-value recovery of lees, cultivation of photosynthetic bacteria and preparation of biochar according to claim 1, characterized in that: The photosynthetic bacteria culture temperature in S4 is 30-35° C., the pH is 7.0-7.5, and continuous illumination is performed at a light intensity of 2000 Lux in an anaerobic environment.

5. The integrated method based on high-value recovery of lees, cultivation of photosynthetic bacteria and preparation of biochar according to claim 1, characterized in that: The conditions of the pyrolysis process in S5 are: heating in a tube furnace at 500-600° C. for 1-2 hours while continuously purging with nitrogen to maintain an oxygen-free environment.

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