Method of combined dry-wet digestion for poultry manure and straw

Abstract

The invention relates to a dry and wet combined digestion treatment method for livestock manure and straw. The method mainly comprises steps as follows: mixing a separation liquid after separation of cow dung with an inoculum, and performing wet anaerobic digestion on the mixture to produce first biogas and a digestion liquid; mixing and turning the straw and the livestock manure except the cow dung to obtain a first mixed material, mixing the first mixed material with the digestion liquid to obtain a second mixed material, and performing dry digestion treatment on the second mixed material to produce second biogas, biogas slurry and biogas residues; collecting and feeding the first biogas and the second biogas into a power generating set after desulfurization and dehydration; feeding the biogas residues into an organic fertilizer production line, and recovering the biogas slurry to the dry anaerobic digestion process for recycling. According to the method, dry and wet combined digestion is adopted, dry aerobic digestion is performed before dry anaerobic digestion, meanwhile, backflow of leachate is performed, mutual contact and actions among the material, microbes and moisture are enhanced, and the problems of crusting of materials, thickening of fermentation broths and difficulty in mass and heat transfer during dry fermentation are solved.

Description

technical field [0001] The invention relates to a method for processing organic waste from agriculture and animal husbandry, in particular to a method for combined dry-wet digestion using poultry manure and straw as raw materials, and belongs to the technical field of agricultural and animal husbandry waste treatment. Background technique [0002] With the tremendous development of the rural economy, farmers began to gradually change the traditional way of energy consumption and fertilizer use in production, making the problem of excess agricultural waste increasingly prominent and becoming an important source of pollution to the ecological environment. The degree of harmless treatment of domestic garbage and livestock and poultry manure is very low, and the phenomenon of on-site stacking is serious; the comprehensive utilization rate of agricultural waste (such as straw) is not high, and random incineration and random abandonment are common. This has caused serious pollutio...

AI Technical Summary

Problems solved by technology

However, this treatment method has the following problems: the raw material is single, and the fermentation process is not suitable for the diversity of raw materials; and the water consumption is large, and the biogas slurry and residue generated by the reaction need to be treated twice; Preprocessing requirements are relatively high

However, the disadvantages of this treatment method are: difficult stirring, resulting in poor mass and heat transfer, low gas production rate, and difficult to achieve continuous feeding and discharging

[0004]In most dry-type fermentation projects, due to the relatively high dry matter content, high viscosity of the fermentation broth, straw-like materials are easy to crust, and it is difficult to feed and discharge materials. Most of them require The more expensive plunger pump feeds and discharges the material, which is easy to block

There is also a garage-type dry fermentation used for urban organic waste treatment, which has the disadvantages of high investment and complex equipment structure

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