Method for producing methane through fungal solid-state fermentation of kitchen waste

Abstract

The invention discloses a method for producing methane through fungal solid-state fermentation of kitchen waste. The method comprises the following steps: sorting a certain amount of kitchen waste forimpurity removal, and then mechanically crushing to form kitchen waste to be treated; selecting 5-20% of the kitchen waste to be treated, and adding fungal aspergillus awamori and aspergillus oryzaefor solid-state fermentation to culture a solid substance rich in amylase and proteinase; adding the cultured solid substance rich in the amylase and the proteinase into water-mixed kitchen waste forhydrolyzing to form a hydrolyzate rich in small molecular nutrient substances (glucose and amino acids); successively performing solid-liquid separation and oil-water separation on the hydrolyzate toprepare a kitchen waste hydrolyzate; adding the kitchen waste hydrolyzate into an anaerobic fermentation tank for producing the methane. According to the method, the amylase and the proteinase are cultured through the fungal solid-state fermentation to hydrolyze the kitchen waste, so that the hydrolysis and liquefaction speed of the kitchen waste can be increased, the utilization rate of a substrate is increased, and further the yield of the methane is increased.

Description

technical field [0001] The invention relates to the technical field of kitchen waste treatment, in particular to a method for producing methane by using fungi to solid-state ferment kitchen waste. Background technique [0002] Kitchen waste is the main part of municipal solid waste, accounting for about 30%-40%. Its treatment is an important link to solve the problem of municipal solid waste. Food waste is mainly composed of organic components, with an average total starch content of 22.3-31.4%, and a crude protein content of 14.2-19.1%, which has high resource utilization value. Traditional domestic waste treatment methods such as landfill and incineration are adopted. There are certain disadvantages, and anaerobic digestion technology has been widely used as an ideal treatment method. [0003] However, there are still some key scientific and technical problems in the current anaerobic fermentation methane production process of food waste: [0004] (1) see figure 1 , sho...

AI Technical Summary

Problems solved by technology

[0004] (1) see figure 1 , shows the four stages of anaerobic fermentation of food waste to produce methane. The nutrients in food waste usually exist in the form of macromolecules (such as starch and protein), and these macromolecular nutrients need to be hydrolyzed to produce small molecular nutrients (such as glucose and amino acids), it can be used by microorganisms to ferment methane, and this hydrolysis process is the rate-limiting step of anaerobic fermentation of food waste to methane, which increases the cost of methane production;

[0005] (2) Unlike liquid organic waste, most of the nutrients in food waste exist in solid form, resulting in low substrate utilization, which in turn leads to low output of methane produced by anaerobic fermentation of food waste;

[0006] (3) Food waste contains a large amount of oil. During the process of anaerobic fermentation to methane, these oils will adhere to the surface of fermenting methanogenic microorganisms, inhibit the activity of methanogenic microorganisms, and reduce the specific surface area of ​​the substrate in contact with microorganisms. , thus affecting the methane production efficiency of the anaerobic fermentation methane production system

Images