Anaerobic digestion (AD) is a series of natural biological processes whereby organic waste material is broken down by micro-organisms and converted into energy, known as biogas.A typical anaerobic digester is a sealed vessel, or series of vessels, in which bacteria act without oxygen. The organic material contents need to be fully mixed and warmed, usually to blood temperature. Biogas is the name given to the mixture of gases formed during the anaerobic digestion of organic wastes. Biogas consists of methane (c70%) and carbon dioxide (c30%).It can be used in stationary engines to generate electricity, but it is not suitable as a vehicle fuel. Online Journals are scholarly and peer reviewed journals. The journals provide forum and motivates scientists, researchers, academics, engineers, and practitioners in all aspects to share their professional and academic knowledge in the fields computing, engineering, humanities, economics, social sciences, management, medical science, and related disciplines. Online Journals also aims to reach a large number of readers worldwide with original and current research work completed on the vital issues of the above important disciplines.