Three-phase multi-stage anaerobic fermentation system for high-solid-content organic waste and biogas production method thereof

Abstract

The invention provides a three-phase multi-stage anaerobic fermentation system for high-solid-content organic waste and a biogas production method thereof. The three-phase multi-stage anaerobic fermentation system comprises a hydrolysis pretreatment tank, an acidolysis tank, a horizontal anaerobic fermentation tank, a vertical anaerobic fermentation tank and a biogas storage tank, wherein the hydrolysis pretreatment tank, the acidolysis tank, the horizontal anaerobic fermentation tank and the vertical anaerobic fermentation tank are connected in series and are respectively equipped with a stirring device, a hot water inlet and a biogas slurry reflux inlet; gas produced by the acidolysis tank is sent to the horizontal anaerobic fermentation tank through a one-way valve; biogas generated inthe horizontal anaerobic fermentation tank and the vertical anaerobic fermentation tank is collected into the biogas storage tank; and biogas residues and biogas slurry generated by the vertical anaerobic fermentation tank enter a biogas slurry pool for filtration separation, the biogas slurry is subjected to biogas slurry reflux, and the biogas residues are used for the preparation of organic fertilizers. A set of three-phase anaerobic fermentation process is established in the invention according to the biochemical reaction chain (hydrolysis-acidification-methanation) of anaerobic bacteria,conforms to the group enrichment effect of anaerobic bacteria, and allows the hydraulic retention time of materials to be shortened from common 20-30 days to about 15 days and the decomposition rate of the materials to be 96% or more.

Description

technical field [0001] The invention belongs to the technical field of organic waste treatment to produce biogas, and relates to a three-phase multi-stage high-solid organic waste anaerobic fermentation system and a method for producing biogas. Background technique [0002] With the increase of organic waste in my country year by year, organic waste (including crop stalks, livestock and poultry manure, municipal waste, etc.) has not only become a major environmental hazard in my country, but is also regarded as a misplaced resource. [0003] The high-solid anaerobic fermentation organic waste treatment technology is to convert organic macromolecules into small molecules through the biochemical degradation reaction of anaerobic bacteria, and convert organic macromolecules into small molecules in the acid hydrolysis stage. acid, and finally in the methanation stage, methane bacteria produce biogas and biogas slurry, and the biogas slurry can be further processed into organic f...

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Problems solved by technology

[0004] At present, most of the high-solid anaerobic fermentation organic waste treatment technologies are single-phase systems. The three stages of hydrolysis, acidolysis and methanation work together in one reactor. Although this method is simple to implement, it has many shortcomings. : (1) It is not conducive to the enrichment effect of anaerobic microorganisms, the doubling efficiency of anaerobic microorganisms is not high, and the gas production is unstable; (2) It is not conducive to the growth of methanogens, because the acidolysis process takes less time than the methanation process , forming excessive accumulation of organic acids, severe acidification can cause a large number of death of methane bacteria, reduce gas production efficiency, and interrupt anaerobic fermentation; (3) It is not conducive to the independent regulation of biochemical reactions at different stages. At this time, the entire anaerobic reaction will stagnate, and the single-phase system must replace all the materials, re-inoculate, and restart the system. Each restart of the system will consume a lot of time and energy. The single-phase system is due to the "short circuit" phenomenon caused by the interruption of the reaction chain. It is a problem that has been criticized for a long time in the process of anaerobic fermentation

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