Relative effectiveness of biogas production using poultry wastes and cow dung
Keywords:Biogas production, bio-digester, poultry wastes, cow dung, biogas volume and yield.
A comparative study of biogas production of different proportions of poultry wastes and cow dung was conducted under the same operating conditions. The study was based on Completely Randomsied Design replicated three times. Three different mix ratios of poultry wastes and cow dung were tested (namely 3:1, 1:1 and 1:3) and all of them were diluted with the same amount of water. Each treatment was replicated three times. Biogas production was measured for a period of seven days and volume of gas produced was determined by water displacement method at room temperature of 25 – 30oC. Biogas production started on the second day, and reached apex on the sixth day for Digester A (cow dung:poultry wastes r = 1:3). Production reached its peak on the seventh day for Digester B (cow dung:poultry wastes r = 2:2). For Digester C (cow dung:poultry wastes r = 3:1), biogas production started on the second day and attained maximum on fifth day. The average gas production for Digesters A, B and C were 3.84, 3.55, and 3.19 mL respectively. The study shows that the largest volume of biogas production was obtained using the 3:1 mix ratio of poultry wastes to cow dung. Poultry wastes therefore are effective for production of biogas than cow dung. Statistical analysis reveals that wastes fed into the digester and days of experiment were significant at 99% confidence level. The volumes of wastes generated by the digesters were statistically different from each other. Digester A produced the highest mean biogas of 4.48 mL/day and this value was significantly higher than ones produced by Digesters B and C (4.26 and 3.72 mL/day respectively). Finaly, for a developing country like Nigeria, where wastes are not productively used, wastes generated from animal wastes can be effectively managed through conversion into biogas. Wastes are therefore turned to wealth, which increases the income of the society.
Keywords: biogas production, bio-digester, poultry wastes, cow dung, biogas volume and yield