Development of a new innovative technological process for continuous methane fermentation in a three-stage biogas plant

Due to economic growth in agriculture, the number of cattle in fattening and dairy farms is increasing, which generates a huge amount of renewable raw materials every day-solid and liquid cattle manure. The purpose of the study is to develop a technology with coarse and fine grinding of cattle waste, with continuous methane fermentation of the substrate and the determination of significant parameters for optimisation and management. The study allowed developing a small-sized new three-stage methane fermentation biogas plant with innovative elements: coarse and fine grinding of solid and liquid cattle manure, which allows increasing the yield of biogas, due to the uniformity of the substrate and due to 12% of the dry matter content in the raw materials, up to 30%; simultaneous heating of the lower part and the circulating water inside the bioreactor, which reduces the amount of biogas produced for heating the main nodes of the biogas plant. The novelty of this work consists of presenting a fundamentally new technological process scheme and showing the experimental data of the dynamics of biogas output. The developed three-stage biogas plant for methane fermentation, affordable and in terms of the amount of raw materials produced daily on the farm, when implemented, would allow the farmer to dispose of livestock waste and obtain biogas (methane) used to generate electricity and heat.

Automated summary

Due to economic growth in agriculture, the number of cattle in fattening and dairy farms is increasing, resulting in a large amount of solid and liquid cattle manure. This study developed a three-stage methane fermentation biogas plant with coarse and fine grinding of cattle waste to optimize and manage the biogas production. The innovative elements of the plant include uniformity of the substrate, increased biogas yield, and reduced energy consumption for heating. The implementation of this plant would enable farmers to dispose of livestock waste and generate electricity and heat using biogas.