Method and device for producing methane by using dry anaerobic digestion for urban sludge and organic matter

Abstract

The invention belongs to the field of reclamation of solid wastes, in particular relating to a method and a device for producing methane by using a dry anaerobic digestion for urban sludge and an organic matter. The device comprises a reaction chamber and a double-layer helix ribbon type agitator and is provided with a feed inlet and outlet, a sample port, a temperature-setting controller, a methane metering device, a stirring control device and others devices. The method comprises the following steps: dewatering sludge is placed into a fermentation tank for inoculation and seal, the revolving speed at start-up stage is 5-15r / min and daily stirring time is 12h, the revolving speed at acid-producing stage is 10-20r / min, intermittent operation is carried out; the daily stirring time is morethan or equal to 8h and less than or equal to 16, and starting and stopping frequency for the motor is required to be increased; temperature control is performed at acid-producing stage and methane-producing stage and material temperature is controlled to be 35+ / -1 DEG C; and after finishing the fermentation, one fourth to one third of biogas residues are left for being used as inoculum for the next batch of fermented materials and the rest of residues are discharged. The invention can be applied to reclamation treatment of the urban sludge and can obviously save equipment investment and landoccupation compared with the wet fermentation.

Description

technical field [0001] The invention belongs to the field of solid waste recycling, and specifically relates to a method and a device for producing biogas by dry-process anaerobic fermentation of urban sludge and organic matter (such as poultry manure, kitchen waste, etc.). Background technique [0002] The amount of dewatered sludge produced by urban sewage treatment plants due to the purification of domestic sewage is huge. At present, the annual collection capacity is about 26 million tons. The treatment and disposal of sludge in sewage treatment plants mostly use concentration and dehydration followed by landfill. This method not only occupies limited land resources, but also easily causes secondary pollution. In addition, cities generate a large amount of organic waste every day, such as poultry manure and kitchen waste. The resource utilization rate of these waste landfills is low, which does not conform to the principle of sustainable development in our count...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to overcome the difficulties of mass transfer, difficult enrichment of methane bacteria and difficulty of gas overflow due to the characteristics of high viscosity, no fluidity, and no void ratio in the dry fermentation process of municipal sludge, and overcome other dry fermentation methods. The shortcoming that the equipment cannot achieve efficient microscopic mixing of sludge provides a method and device for producing biogas by dry anaerobic fermentation of municipal sludge and organic matter

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