Introduction – Biogas is a mixture of about 50 – 75% methane and 25 – 50% CO2 and other trace contaminants. The gas is created from anaerobically decaying organic matter, such as manure and plant material. As the gas is man-made, it is differentiated from natural gas.
Biogas is produced by means of a process known as anaerobic digestion. It is a process whereby organic matter is broken down by microbiological activity and, as the name suggests, it is a process which takes place in the absence of air. It is a phenomenon that occurs naturally at the bottom of ponds and marshes and gives rise to marsh gas or methane, which is a combustible gas.