Technology for methane production through aerobiotic acidification and anaerobic fermentation by means of straw

Abstract

The invention relates to a technology for methane production through aerobiotic acidification and anaerobic fermentation by means of straw. According to the technology, a large amount of agricultural wasted straw is used as the main material, the aerobiotic acidification and anaerobic fermentation two-phase methane production process is conducted, solid-liquid separation is conducted on biogas slurry obtained after fermenting methane, the solid part can directly serve as organic fertilizer without dewatering, and the liquid part is recycled into an aerobiotic acidification tank for acidolysis; no waste water is discharged in the whole process. By adopting the aerobiotic acidification and anaerobic fermentation two-phase fermentation process, placing acid-forming bacteria and methanogens in two reactors respectively and conducting acidification through the aerobic reaction, biogas loss and propionic acid accumulation caused by methanogens during acidification are avoided, the time for anaerobic fermentation of biogas is shortened, and biogas producing efficiency is improved.

Description

technical field [0001] The invention belongs to the technical field of biomass energy, and in particular relates to a production process for producing biogas by aerobic acidification and anaerobic fermentation of straw. Background technique [0002] China is a large agricultural country and one of the countries with the richest straw resources in the world. In recent years, straw biogas projects have attracted more and more attention. The use of crop straws for anaerobic fermentation to produce biogas is a clean and efficient way to use straw as energy. [0003] The biogas fermentation process is a complex biochemical treatment process, which consists of an acidogenic stage and a methanogenic stage. The current biogas fermentation adopts a one-stage or two-phase anaerobic fermentation process, which has its corresponding shortcomings. [0004] In the one-stage reaction, acid-producing bacteria and methanogenic bacteria are grown in the same reactor. Because the growth cha...

AI Technical Summary

Problems solved by technology

The current biogas fermentation adopts one-stage or two-phase anaerobic fermentation process, which has its corresponding shortcomings.

[0004] The one-stage reaction grows acid-producing bacteria and methanogenic bacteria in the same reactor. Because the growth characteristics of these two types of microorganisms are very different, it is difficult to exert their respective optimal performance

Especially when straw is used as the main raw material, the biodegradability of crop straw cannot be fully and timely improved in the acid production stage, so that it cannot provide timely and appropriate nutrient supply for the methane production stage, thus affecting the gas production efficiency of biogas, and the reaction The time is long, and the amount of straw added in the process should not be too high, resulting in a low volumetric gas production rate