CN-121975871-A - Multi-parameter regulated high-cellulose organic waste anaerobic digestion treatment method

Abstract

The invention belongs to the technical field of organic waste treatment, and particularly relates to a multi-parameter-regulated high-cellulose organic waste anaerobic digestion treatment method. According to the method provided by the invention, alkali liquor, hydrothermal or biogas slurry pretreatment is carried out on high-cellulose wastes such as Chinese medicinal residues, olive residues and vinasse, reducing sugar, volatile fatty acid (mainly acetic acid) and ammonia nitrogen content are synchronously monitored, and pretreatment conditions are dynamically adjusted according to a preset threshold (reducing sugar is less than or equal to 50mg/g, acetic acid is obviously higher than propionic acid, and ammonia nitrogen is less than or equal to 7 mg/g). The invention realizes the cooperative regulation and control of hydrolysis promotion and digestion stability, effectively avoids acidification and ammonia inhibition, improves the methane yield and the system operation stability, and is suitable for the efficient anaerobic digestion treatment of various high-cellulose organic wastes.

Inventors

• REN DONG
• LIU SHIDA
• TANG XINYING
• WU HAORAN
• ZHOU YUAN
• LUO YU
• TANG XIUZHEN
• REN MINGXU
• HE QIN

Assignees

• 西华师范大学

Dates

Publication Date

20260505

Application Date

20260204

Claims (8)

1. 1. The multi-parameter regulated high-cellulose organic waste anaerobic digestion treatment method is characterized by comprising the following steps of: S1, pretreating high-cellulose organic waste, wherein the pretreatment comprises at least one of alkali liquor pretreatment, hydrothermal pretreatment and biogas slurry presoaking pretreatment; S2, monitoring the release amount of reducing sugar, the content of volatile fatty acid and the content of ammonia nitrogen in the pretreated material; And S3, carrying out anaerobic digestion on the materials with the release amount of the reducing sugar, the volatile fatty acid content and the ammonia nitrogen content meeting the preset cooperative regulation and control threshold, wherein the release amount of the reducing sugar in the cooperative regulation and control threshold is not higher than 50mg/g, the release amount of acetic acid in the volatile fatty acid is obviously higher than that of propionic acid, and the ammonia nitrogen content is not higher than 7mg/g.
2. 2. The method of claim 1, wherein the high cellulose organic waste is selected from at least one of Chinese herb residues, olive residues, distillers grains.
3. 3. The method according to claim 1, wherein in the lye pretreatment, lye comprises a NaOH solution, the mass fraction of the NaOH solution is 2% -10%, and the lye pretreatment time is 0.5 hours to 6 hours.
4. 4. The method according to claim 1, wherein the hydrothermal pretreatment is performed at 100 ℃ to 140 ℃ for 10 minutes to 120 minutes with a solid-to-liquid ratio of 0.5 to 1.5:5 to 15.
5. 5. The method according to claim 1, wherein in the pre-soaking pretreatment of the biogas slurry, the ammonia nitrogen concentration of the biogas slurry is 0.5-2.0 g/L, the pre-soaking time is 4-120 hours, and the solid-liquid ratio is 0.5-1.5:4-8.
6. 6. The method of claim 1, wherein the anaerobic digestion step comprises mixing the material, biogas slurry and water, introducing N 2 , stripping off oxygen from the bottle, and anaerobic fermentation at 37 ℃.
7. 7. The method of claim 6, wherein the mass ratio of the material, biogas slurry and water is 40-60:260-340:30-60.
8. 8. The method of claim 7, wherein the N 2 blow-off time is 1min.

Description

Multi-parameter regulated high-cellulose organic waste anaerobic digestion treatment method Technical Field The invention belongs to the technical field of organic waste treatment, and particularly relates to a multi-parameter-regulated high-cellulose organic waste anaerobic digestion treatment method. Background Anaerobic digestion technology is widely applied to the treatment process of kitchen waste, agricultural waste and industrial organic solid waste because of the capability of reducing and stabilizing organic waste and recycling energy. Among them, high-fiber organic waste is an important treatment object in the field of anaerobic digestion due to wide sources and high recycling potential. However, such high fiber organic waste typically contains significant amounts of cellulose, hemicellulose, and lignin, which are compact in structure, high in crystallinity, and poorly accessible to microorganisms, resulting in the hydrolysis stage being a rate limiting step of anaerobic digestion, thus making methane yield and reaction rate significantly lower than theoretical levels. In order to improve the anaerobic digestion performance of fibrous organic waste, hydrothermal treatment, chemical treatment, biological treatment and combination thereof are commonly adopted in the prior research and engineering practice to destroy the lignocellulose structure and promote the release of soluble organic matters. Based on this, some prior arts try to quantitatively evaluate the pretreatment effect by introducing concepts such as "pretreatment strength" or "degree of structural destruction", and further establish an association between the evaluation result and anaerobic digestion performance. For example, the anaerobic digestion potential is predicted by constructing an intensity index through parameters such as temperature, time, chemical agent addition amount and the like, or by representing the pretreatment effect through fiber degradation rate, crystallinity change and the like. The technical thought is helpful to comparing the influence of the structural change of the raw materials on the anaerobic digestion performance under different pretreatment conditions to a certain extent, but the evaluation system is often focused on single dimension or single type indexes, and the promotion effect of pretreatment on the structure or hydrolysis degree of the raw materials is mainly reflected. Although the prior art can enhance the hydrolysis process by increasing the pretreatment strength or improving the fiber structure, the following problems still remain in practical use: (1) Evaluation index and anaerobic digestion stability disjoint The prior art takes the degree of fiber degradation or the release amount of soluble organic matters as an evaluation basis, and defaults to the fact that the more complete the hydrolysis is, the better the anaerobic digestion performance is. However, in an anaerobic digestion system, the hydrolysis products are not directly converted to methane, and their subsequent conversion process is highly dependent on the dynamic equilibrium between acidogens and methanogens in the system. When the pretreatment leads to the massive release of soluble organic matters or intermediate metabolites in a short time, the rapid accumulation of volatile fatty acids is easy to be initiated, and the acidification of the system is further caused, so that the activity of methanogens is inhibited, and the actual methane yield is reduced. (2) Ignoring synergistic effects of inhibitors such as ammonia nitrogen The high fiber organic waste is typically accompanied by a proportion of nitrogen-containing organics, which can release ammonia nitrogen during pretreatment and anaerobic digestion. In the prior art, when the pretreatment effect is evaluated, the ammonia nitrogen concentration is often not included in the constraint condition parallel to the hydrolysis degree, so that the pretreated material may be in a potential inhibition state when entering the anaerobic digestion stage. (3) Lack of overall control thought oriented to anaerobic digestion process The prior art focuses on whether pretreatment is sufficient or not, but less on comprehensive judgment of digestibility, stability and inhibition risk of pretreated materials from the perspective of the whole anaerobic digestion process. Therefore, even if the pretreatment strength evaluation result is excellent, problems such as slow start, process fluctuation or unstable gas production may occur in the actual digestion process. In summary, the prior art lacks a pretreatment regulation method capable of simultaneously combining hydrolysis promoting effect and anaerobic digestion process stability. Especially when treating high-fiber organic waste, how to avoid accumulation of inhibiting factors such as volatile fatty acid, ammonia nitrogen and the like while improving release of degradable organic matters is still a key technical bottleneck restricting improvem