Method for producing methane through high-temperature dry type anaerobic co-fermentation

Abstract

The invention discloses a method for producing methane through high-temperature dry type anaerobic co-fermentation. The method comprises the following steps that 1, livestock feces and urine, crop straw and water are mixed according to the mass ratio of 4:(0.5-3.5):(0-4) to obtain a mixed material, the solid content of the mixed material ranges from 20% to 40%, VS ranges from 15% to 25%, and C / N ranges from 20 to 35; 2, a biogas inoculum and the mixed material are mixed according to the weight ratio of 1:1, then the mixture is placed in an anaerobic fermentation tank, nitrogen is introduced into the anaerobic fermentation tank for 10-20 min, and the fermentation temperature ranges from 55+ / -2 DEG C; 3, the sludge retention time ranges from 20 days to 40 days. According to the method, the problems of high-concentration ammonia fermentation inhibition and organic acid accumulation can be effectively relieved, the biogas content in the whole anaerobic fermentation process can be improved by 15% to 40%, the methane yield can be improved by 15% to 45%, and finally it can be guaranteed that methane is continuously and efficiently produced by a fermentation system.

Description

technical field [0001] The invention belongs to the field of fermentation, and specifically relates to a method for producing methane by high-temperature dry anaerobic co-fermentation. Background technique [0002] Anaerobic fermentation technology uses the synergistic cooperation of a variety of microbial flora to decompose organic components in agricultural waste into methane and carbon dioxide through multi-stage anaerobic decomposition such as hydrolysis to produce acid and gas. Among them, methane can be used as energy to generate heat and generate electricity. There are various forms of agricultural waste, and according to its composition, it is mainly divided into two categories: livestock manure and crop straw. Mixing livestock and poultry manure and straw can adjust the C / N ratio of materials to facilitate anaerobic fermentation treatment by microorganisms. Therefore, the conversion of livestock and poultry manure and crop straw into methane through mixed anaerobic ...

AI Technical Summary

Problems solved by technology

Even under high temperature conditions for anaerobic fermentation, low microbial diversity and high decomposition rate lead to poor system stability and low gas production efficiency

In the dry anaerobic fermentation system, due to the high concentration of dry matter, it will cause inhomogeneous mixing of the reaction substrate, uneven heat and mass transfer, and high concentration of ammonia inhibits fermentation and accumulation of organic acids.

Although the inhibition of ammonia can be alleviated by adjusting the mixing ratio of different reaction materials to achieve a certain improvement effect, but under long-term operating conditions, NH 4 + The gradual increase of -N concentration and the accumulation of organic acids will affect the stability of the long-term operation of the high-temperature dry anaerobic fermentation system

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