Operation of a Domestic Biogas Plant in an Urban Setting in a Developing Country-A Field Experience

Abstract

The main source of fuel for cooking and other domestic applications in most developing countries (especially in sub-Saharan Africa) is fuel wood. This source of fuel is not only non-renewable but leads to deforestation and its attendant contribution to global warming. Coal and charcoal, which are also used where available, equally contributes to environmental problems. In countries like Nigeria where there is abundance of fossil fuel, cooking gas and kerosene are unfortunately hardly available and/or affordable to majority of the low income families that should rely on this source of fuel. Electricity supply is erratic and unreliable. Biogas therefore appears to be a credible alternative fuel for cooking and other purposes in such countries. Biogas is a major product of anaerobic fermentation of biodegradable organic waste. It has a calorific value of about 22.4 MJ/ m3 and contains about 50-60% methane. 30-45% carbon dioxide and a small percentage of hydrogen sulfide, hydrogen, carbon monoxide, ammonia, water vapour and mercaptans. The gas is useful as a fuel substitute for firewood, dungs and agricultural residues as well as for petrol and diesel for electricity generation.