Biogas Production from the Co-digestion of Cow dung and poultry Droppings Using a Plastic Cylindrical Digester

Abstract

This study was carried out to compare the rate and amount of gas produced from the codigestion of two different substrates of cow dung and poultry droppings under anaerobic conditions. Biogas production from three(3) cylindrical bio-digesters containing cow dung, poultry droppings, and a mixture of cow dung and poultry droppings under an average temperature of 28 oc and a pH of 6.2 was examined. In each case, the feedstock was diluted with an equal volume of water to form a slurry. The digestion took place for 35 days. The biogas produced during this period was collected by the balloon method and subsequently measured and recorded. The results obtained from this study show that the co-digestion of cow dung and poultry droppings yielded a maximum volume of 2.62 cm³, while poultry droppings yielded 2.50 cm³ and cow dung yielded 1.78 cm³. Thus, the co-digestion of the feedstocks gave a better gas production, and the mean biogas yield was found to be significant (P<0.05) compared to each of the single substrates. This study has demonstrated that the co-digestion of cow dung and poultry droppings in a plastic cylinder could be a cheap method for locally producing biogas for domestic purposes. It is, however, recommended that gas production can be enhanced during hot seasons where higher temperature is easily attained.