Method for producing biogas and organic fertilizer by dry fermentation of livestock and poultry feces

Abstract

The invention discloses a method for producing biogas and organic fertilizer by dry fermentation of livestock and poultry feces. The method comprises the following steps of feeding directly solid livestock and poultry feces of which dry matter concentration is above 15% into a biogas fermentation device, or mixing the solid livestock and poultry feces and livestock and poultry feces fermentation residues and then feeding the mixture into the biogas fermentation device to carry out biogas production, wherein the fermentation residues obtained by the previous step can be utilized as organic fertilizer or the fermentation residues are subjected to composting and then are utilized for organic fertilizer production. Through the method provided by the invention, livestock and poultry feces is subjected directly to dry fermentation without dilution and desanding pretreatment; scum is not formed in the biogas fermentation device; temperature rise and heat preservation are easy; nutrient loss is less; and produced organic fertilizer has high fertilizer efficiency.

Description

technical field [0001] The invention relates to a method for producing biogas and organic fertilizer by dry fermentation of livestock and poultry manure, which belongs to the field of solid waste treatment and biogas engineering in environmental engineering, and is mainly used for the treatment of solid manure in large-scale livestock and poultry farms. Background technique [0002] In the prior art, for the treatment and utilization of livestock and poultry manure, there are mainly the following methods: [0003] The first is the incineration method, which uses waste incineration treatment technology to ash it at 800-1000°C, and the heat generated is used for power generation, etc., to achieve the purpose of reducing and killing harmful pathogens. This method requires large investment, expensive treatment costs, and produces a large amount of harmful gases during the treatment process, making it difficult to apply and promote. [0004] The second is the drying method, ...

AI Technical Summary

Problems solved by technology

At present, wet fermentation technology is mainly used, which is to mix feces with flushing sewage, prepare a feed liquid with a total solid concentration (TS) of less than 10%, and then enter the biogas fermentation device. It has the advantages of fast start-up, convenient feeding and discharging, and mature management. However, The main problems of this technology are: the amount of biogas slurry and biogas residue is large, the nutrient content is low, and it is difficult to fully utilize it. In addition, for the manure with a lot of sand, such as chicken manure and cow manure, it is difficult to pretreat and remove sand, and the biogas fermentation device is easy to accumulate. Sand, and it is not easy to discharge, thereby reducing the effective volume of the device, and eventually leading to the scrapping of the system