Comparative evaluation of biogas production from Poultry droppings, Cow dung and Lemon grass

•Biogas was generated efficiently from Poultry droppings, Cow dung and Lemon grass.•Lemon grass produced less volume but better quality gas than other two substrates.•Lemon grass also showed highest cooking rate in the cooking test conducted.•Anaerobic digestion was efficient in pathogen and some parameters reduction.

The study explored the production of biogas from Lemon grass, Cow dung and Poultry droppings. The three substrates were pre-fermented according to standard methods. Six (6) kg of each pre-fermented substrate was mixed with water in ratio 1:1 v/v to form slurry and digested for 30 days. A total of 0.125 m3, 0.191 m3 and 0.211 m3 of biogas were respectively produced from the Lemon grass, Cow dung and Poultry droppings with deviations of 0.00234 m3, 0.00289 m3 and 0.00484 m3 respectively. The cooking test carried out revealed that the scrubbed gas had higher cooking rates for water (0.12 L/min, 0.085 L/min and 0.079 L/min for Lemon grass, Cow dung and Poultry droppings respectively) while the cooking rates for unscrubbed gas were 0.079 L/min, 0.064 L/min and 0.06 L/min respectively. The pH of the medium fluctuated optimally between 6.5 and 7.8. The research demonstrated that Lemon grass produced less volume but better quality biogas compared to Cow dung and Poultry droppings.