Biogas is generated from the anaerobic digestion of organic matter. Biogas is generated in landfill sites since organic matter such as domestic food and garden waste is buried and compressed in a dark oxygen free environment. For decades after a landfill site is filled biogas continues to be generated and released into the atmosphere.
What Does Biogas Contain
Biogas is made up primarily of Methane and Carbon Dioxide, but can also contain small quantities of Nitrogen, Hydrogen, Hydrogen Sulphide, and even Oxygen. With processing biogas can be cleaned up to make a substitute for natural gas which can therefore be pumped to homes and businesses for cooking and heating etc.
Collecting and Using Biogas
Biogas has to be collected from landfill sites by drilling gas wells. Historically it was just flamed (i.e. burnt off) but now more and more landfills are collecting the gas generated for power generation. Some sites have even built dedicated Anaerobic Digesters to generate larger quantites of methane-rich biogas more quickly and to reduce the volume of the waste to be buried.
Biogas Powered Vehicles
Biogas can be used to power vehicles. There is a biogas powered train in Sweden running between Linkoeping and Vaestervik which is powered with gas generated from cow waste and sewage. From well to the vehicle diesel generates 20 times more carbon dioxide than biogas. Biogas also has no particulate emissions and generates one-fifth as much nitrous oxide emissions as diesel.