Wuhan Qianzishan Waste Treatment Plant believes that the treatment of organic waste and the recycling of resources are of great significance to optimize my country's energy structure, develop a circular economy, improve the ecological environment, and build a resource-saving and environment-friendly society. Organic waste dry anaerobic fermentation technology comprehensive treatment of municipal solid waste and other organic solid waste, and the production of biogas and organic fertilizer. Its advantages are low water content, no sewage generated in the reaction process, low operating energy consumption, high treatment efficiency, high energy efficiency, and fermentation residue can be directly used as organic fertilizer. Can achieve waste reduction, harmless and resource treatment.

Wuhan Qianzishan Waste Treatment PlantthinkThe treatment of organic waste and the recycling of resources are of great significance to optimize China's energy structure, develop circular economy, improve the ecological environment, and build a resource-saving and environment-friendly society. Organic waste dry anaerobic fermentation technology comprehensive treatment of municipal solid waste and other organic solid waste, and the production of biogas and organic fertilizer. Its advantages are low water content, no sewage generated in the reaction process, low operating energy consumption, high treatment efficiency, high energy efficiency, and fermentation residue can be directly used as organic fertilizer. Can achieve waste reduction, harmless and resource treatment.

Wuhan Qianzishan Waste Treatment PlantthinkAt present, there is no mature dry fermentation process with independent intellectual property rights in China, and it is still in the exploratory stage. In the process of engineering application, there are problems such as heating, heat preservation, low fermentation efficiency, blockage, and sealing of fermentation warehouse. Therefore, it is urgent to carry out applied research aiming at industrialization.

Wuhan Qianzishan Waste Treatment PlantthinkAnaerobic digestion refers to the decomposition of organic matter by facultative and anaerobic bacteria under anaerobic conditions.Digestion technology for CH4, CO2, H2O and H2S. Anaerobic digestion is widely used in the treatment of sewage, livestock manure and municipal organic waste. Biogas engineering technology can achieve the goals of developing circular economy, protecting the environment, reducing greenhouse gas emissions and producing renewable energy.

Anaerobic digestion can be divided into four stages: hydrolysis, acidification, acetogenesis and methanogenesis. In the hydrolysis stage, the suspended particulate organic matter such as carbohydrates, protein, and fat in the kitchen waste is hydrolyzed by microorganisms into soluble organic matter such as polysaccharides, polypeptides, and organic acids. In the acidification stage, acid-producing bacteria degrade short-chain organic compounds into glucose, amino acids, volatile fatty acids(VFAs), NH3 and H2S. Acetic acid producing bacteria use glucose and amino acids to produce acetic acid, H2 and CO2. In the methanation stage, methanogens convert acetic acid and H2 to CH4 and CO2.

Wuhan Qianzishan Waste Treatment PlantthinkFood waste is rich in nutrition,The C/N ratio meets the requirements of anaerobic digestion. However, summarizing the literature at home and abroad in recent years, it is found that the anaerobic digestion of kitchen waste still faces many problems:

1) Food waste particles are large, complex organic matter such as lignin, keratin, etc. are difficult to biodegrade under anaerobic conditions, while lignocellulose, cell wall and other compounds are biodegradable, but difficult to bioutilize. These factors will slow down the hydrolysis rate of kitchen waste and prolong the stagnation time of anaerobic digestion.

2) Wuhan Qianzishan Waste Treatment PlantthinkThe generation time of methanogens was longer than that of acid-producing bacteria. Normally, every bacteriaBreeding once every 20 minutes, while methanogens need several days or even dozens of days to reproduce. Therefore, the ability to consume organic acids is limited, and it is susceptible to fluctuations in environmental factors and toxic substances such as heavy metals. Therefore, when the organic load of the system is high, the production and consumption of VFAs are unbalanced, and systematic acidification is easy to occur. In addition, when the protein content of food waste is high, the anaerobic digestion system often faces the problem of ammonia nitrogen suppression,suppressionThe activity of anaerobic microorganisms reduces the gas production efficiency of the system.

3) Wuhan Qianzishan Waste Treatment PlantthinkIn the methanogenic stage, ethanoic methanogens mainly decarboxylate acetic acidCH4 and CO2, while the hydrogen type methane producing bacteria with H2 as the electron donor, CO2 as the electron acceptor, CH4 and H2O generation. However, in the biogas produced by anaerobic digestion of kitchen waste, CH4 accounts for only 40% ~ 70%, and most of the rest are impurities such as CO2 and a small amount of H2S, so the calorific value of biogas products is low.