AN EXPERIMENTAL STUDY FOR THE CHARACTERIZATION OF BIOGAS PRODUCTION FROM COW DUNG AND DROPPINGS

The present work is an account of an ongoing work on biogas production from animal wastes at LEREA (Laboratoire d’enseignement et de recherche en énergétique appliquée) in Mamou, Guinea. The work consists of biogas production from anaerobic digestion and co-digestion of cow dung and droppings. We focus in this report on the determination of the physico-chemical characteristics of the experimental setup. We have carried out three experiments of anaerobic digestion each one lasting 45 days at mesophilic temperature (temperature was maintained in the range 27°C - 28°C). Biogas - 28.4 liters have been obtained from droppings, 22.6 liters from cow dung and 38.7 liters from co-digestion of the previous two wastes. The following physico-chemical characteristcs were observed for cow dung: humidity 43%, dry matter 20.83%, organic matter 57%, density 625kg/m3, carbon content 31%, nitrogen content 1.46%, nitrogen-carbon ratio 21/30. For droppings we measured: humidity 35%, dry matter 65%, organic matter 62%, density 250 kg/m3, carbon content 36%, nitrogen level 1.83%. This characterization was carried out on a sample of 3 g of each type of substrate. These results agree with those of the literature that we were able to compare with. Keywords: anaerobic digestion; anaerobic co-digestion; physico-chimical characterization; cow dung weste; droppings weste; methanation; animal waste