Cattle Dung Biogas as a Renewable Energy Source for Rural Laboratories in Nigeria

The paper investigated the use of cattle dung as an alternative and renewable energy source for Nigerian rural laboratories. The non-availability of electric power supply in most Nigerian rural areas has made it difficult for the researchers in the areas to utilize their wealth of knowledge and experience for reasonable and developmental scientific researches. A digester made of mild steel of radius 0.3m, length 0.6m and 2mm thickness was used based on the design pressure of 1692.83kN/m² (16.93 bars). Pressure gauge and mercury in glass thermometer were installed on the top surface of the digester to measure the digester pressure and temperature respectively. A similar thermometer was used to measure the ambient temperature of the environment where the digester was kept. Pressures and temperatures were monitored, at 12 noon daily, for two weeks. The biogas was compressed in to a gas cylinder after being refined through aqueous sodium hydroxide using a spooter. The compressed gas was then tested for combustion. The results indicated that cattle dung had an hydraulic retention time of 13 days for combustion of the biogas to occur. Chromatography results showed that the raw (unrefined) biogas comprised 56.20% CH4, 39.51% CO2, 0.53% NH3, 1.92% CO, and 1.84% H2S while the refined biogas was composed of 70.29% CH4, 27.82% CO2, 0.00% NH3, 1.55% CO, and 0.34% H2S. The calorific value of the raw biogas was 19.15MJ/m³ when it was 22.62 MJ/m³ for the refined product. Biogas production and usage in Nigerian local areas would encourage researches and improve the standard of education, personal and environmental health and bring about overall national development.