Abstract:
The production of biogas from agricultural waste is seen as one of the alternative source of energy that is being used in most developed and developing countries. In addition, it is a way of solving the environmental pollution and health hazards caused by the emission of dangerous gases from the cow dung when littered. This paper looks at the effect of changing temperature on the rate of production of biogases from cow dung (methane, carbon dioxide, nitrogen), using cow dung of initial moisture content of 77% obtained from a Fulani cow that is feed on 60 % guinea/gamba grass mixed feed and guinea and gamba feed separately. A 2 litre Erlenmeyer flask was used as the batch digester with water as reacting medium. The cow dung was finally diluted to a moisture content of 85%. The result shows that running the experiment at 30, 32, 35, 37 and 38, with 1.4 kg feed weight, the rate of gas production was faster and higher methane composition of 59.02% was obtained at 37oC for the mixed feed thus, faster degradation of waste taking place at this temperature. The average gas production rate at 30 minutes interval was 5.8 millilitres (0.0058 litres) and per minute approximately 0.2 millilitres (0.0002 litres) at 37. The result recorded inconsistencies in the rate of gas production at 30, 32 and 38. For the separate feed intake, cow dung from the guinea grass feed had higher methane composition (50.63%) compared to the gamba grass (48.21%) when ran at 37oC. This indicates that the guinea grass produced more methane gas in the mixed feed than the gamba grass.
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