The EFFECT OF INNOCULUM ON BIOGAS PRODUCTION FROM CASSAVA PEELS

This paper investigated the innoculum effect on cassava peels for biogas production. Cassava peels was mixed with cattle dung and poultry droppings as innoculum by mass into six different combinations. Each mixture was mixed with 12 litres of water before charging to different digesters made of plastics and equipped with mercury-in-glass thermometers and pressure gauges on their top surfaces. The mixtures include 6 kg of cassava peels; 3 kg each cassava peels and cattle dung; 3 kg cassava peels with 3 kg poultry droppings; 2 kg each of cassava peels, cattle dung and poultry droppings; 2 kg cassava peels with 3 kg cattle dung and a kilogram of poultry droppings; and 2 kg cassava peels with a kilogram of cattle dung and 2 kg poultry droppings. The pH of the contents of the digesters was also monitored. The digesters were monitored for 100 days for biogas production in a laboratory at the Federal Polytechnic, Ado-Ekiti, Nigeria. Biogas from each digester was daily tested for combustion as their temperatures and pressures were monitored at 10 am and 4 pm. The results indicated that pH 6.2 for the cassava peels digester. This increased to 7.0 as the quantity of cassava peels reduced in other digesters. The lowest morning ambient and digesters temperatures were respectively 22 oC and 21 oC while the maximum temperatures were 39 oC and 40 oC for the evenings. There were earlier and higher biogas productions with the addition of the innoculum in the digesters. The combustion time of the biogas reduced with increase in the masses of the innoculum