Research and assessment of biogas evolved during anaerobic digestion of biodegradable agricultural waste

Abstract

One of the methods for managing biodegradable waste generating in the Lithuanian agriculture is its anaerobic digestion in a bioreactor. This way of management would allow the recovery of biogas that can be used as an alternative to natural gas. The article analyses agricultural biodegradable waste and its use for the production of biogas in bioreactors. There were performed investigations through anaerobic digestion of pig manure (PM), hen manure (HM) and cow manure (CM) together with green waste biomass (GW) (GW accounted for 1, 2 or 5% of manure of the dry mass). GW is used to improve the ratio of nitrogen and carbon in the substrate (the optimal C:N is 25:1) which predetermines the composition and yield of released biogas. Before the experiment the substrate was prepared so as the dry matter in its content accounted for 10% of the total mass. Investigations were carried out in mesophilic conditions (t = 35 ±1ºC). There were performed measurements of the yield of evolved biogas and methane, oxygen and sulphur hydrogen in it.