A wet-dry combined two-stage anaerobic fermentation biogas production process

Abstract

The invention belongs to the field of solid waste disposal and resource utilization, and in particular relates to a process for production of biogas by wet method-dry method combined two-stage anaerobic fermentation. Broken solid waste and an inoculum are mixed in a full wet type reactor for wet anaerobic fermentation, the wet anaerobic fermentation period hydraulic retention time (HRT) is 5-20 days, after fermentation processing, a fermentation material can be delivered to a dry method fermentation reactor with an infiltration device at the bottom for dry solid fermentation for production of the biogas, and the process combines the dual advantages of wet method fermentation and dry method fermentation. The fermentation process integrating the advantages of fast mass transfer and easy start-up characteristics of the wet method fermentation and reaction space saving of the dry method fermentation, and the like is disclosed. By combination of biomass multistage decomposition and transformation in the fermentation process and methane producing bacteria group enrichment principle, the wet fermentation process advantage is used, the wet fermentation process is used as a homogeneous inoculation stage of the dry method fermentation process, and the problems of difficult inoculation and slow start of the dry method fermentation can be solved.

Description

technical field [0001] The invention belongs to the field of solid waste treatment and resource utilization, and specifically relates to a wet-dry combined two-stage anaerobic fermentation biogas production process. Background technique [0002] my country now has abundant agricultural solid waste resources. The traditional solid waste treatment method is mainly incineration. After harvesting crops, the inorganic material plant ash obtained from solid waste incineration can be used as agricultural fertilizer, forming a cycle of energy reuse. However, this measure is likely to cause atmospheric pollution, endanger human health, destroy the structure of the soil, and even cause fires. Through the biogas project, these resources can be turned into valuables, and while reducing environmental hazards, biogas can be produced as a renewable energy source. The agricultural solid biomass waste is recycled as raw material for biogas projects to produce biogas, and the fermented bioga...

AI Technical Summary

Problems solved by technology

The start-up performance of dry fermentation is not good, but it has the advantages of large processing capacity and no large amount of biogas slurry discharge. Dry fermentation is an important development trend of the biogas industry at home and abroad, but the limitations of slow start and low gas production efficiency have always been Limit the development of dry fermentation technology

However, most of these studies only use the combination of CSTR alone for fermentation, or the combination of CSTR and other wet anaerobic fermentation tanks (such as UASB, ABR, UAFB), and have not changed the small amount and unit of wet fermentation. Disadvantages of small volume gas production

In Chinese patent CN202881263U and Chinese patent CN102212561A, there are techniques related to the combination of dry method and wet method, but these two techniques have not solved the limitations of slow start-up and low gas production efficiency of dry method fermentation, and there are still insufficient start-up performance of dry method fermentation. good defect

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