Disposal and treatment of biological waste represent a major challenge for the waste industry. For a wide range of organic substances from agriculture, foodstuff of feed industries, anaerobic digestion is a superior alternative to composting as it is a net-energy producer. Biogas – a mixture of both methane and carbon dioxide – is created during anaerobic digestion and serves as a high-energy renewable fuel that can be used as a substitute for fossil fuels. Biogas-fuelled engines or biogas upgrading plants improved waste management while maximising the use of an economical energy supply.

Agricultural biogas plants utilise organic materials found on farms to generate biogas, a renewable fuel source and in turn renewable power through cogeneration / combined heat and power. The plant may be designed to accept energy crops that have been grown specifically to input into the digestion facility or agricultural wastes. These crops are typically ensilaged and stored in clamps or hoppers and are continuously fed into the digester throughout the year. In India biogas plants may be called gobar gas plants.

One such way to treat sewage by achieving multi-prong benefit is anaerobic digestion. The technology transforms sewage treatment into a revenue generation option. Whilst effectively treating the sewage, anaerobic digestion generates a high grade of gaseous fuel – sewage gas. The methane produced can be utilised for generating electricity – renewable energy – through a biogas engine thereby making the sewage treatment plant meet its electricity requirements. Moreover, surplus power generated can be supplied to the grid.