Biogas Systems: Principles And Applications (Paperback)

Biogas can be produced by fermenting organic materials in absence of air (or oxygen) with the help of bacteria (micro-organisms) to break down materials to intermediates such as alcohols and fatty acids and finally to methane, carbon dioxide and water. This process is called anaerobic fermentation and was known to exist from quite long time back. Biogas has also been known as the swamp gas, sewer gas, fuel gas, marsh gas, wet gas, and in India more commonly as 'gobar' gas. Natural gas is sis also produced by the action of anaerobic bacteria on plants that grew thousands of years ago. Biogas and natural gas are therefore very much akin to one another. The main fuel component of both is methane gas. However, over the years, pressure and temperature of underground rocks have converted part of the methane in natural gas to other gases such as ethane, propane, butane and the condensate. In contrast, biogas is produced in a digester by anaerobic fermentation. A period of 15 days or so enables anaerobic bacteria to convert organic matter to biogas which however is too short for the conversion of methane to other gases like ethane, propane, butane [35].