Assessment of Mesophilic Co-Digestion of Cow Dung with Lemon Grass for Biogas Production
The scarcity of energy (fossil) and its attendant pollution menace have provided the avenue to consider alternative sources of energy. A study was carried out on the design and construction of an Anaerobic Digester system using 1mm galvanized steel for the production of biogas from co-digestion of Cow dung and Lemon grass sourced from the Zaria abattoir and the University campus respectively. The experiment lasted for 30 days using a 25-liter pilot scale anaerobic digester. A total of 0.146m3(0.100m3after scrubbing) were produced with a deviation and methane content of 0.003 m3 and 68.53% respectively. The cooking test carried out revealed that the scrubbed gas had higher cooking rates for both water and rice (0.10L/min and 0.0048kg/min respectively) than the unscrubbed gas (0.07L/min and 0.0034kg/min respectively while the biogas flow rate was 0.0049m3/min. An improvement of 42.86% and 41.18% was recorded for the cooking rates for water and rice respectively after the gas were scrubbed. The physico-chemistry of the feedstock in the digester revealed the digester temperature fluctuated between 280C and 36.70C while the pH of the medium fluctuated optimally between 5.81 and 7.73.The daily ambient temperatures varied from 31oC to 42oC. The research demonstrated that anaerobic co-digestion of cow dung with lemon grass produced a high quality biogas.