Abstract
Energy is a much crucial necessity for daily errands, either household or industrial. We use it as fuel (transportation or industrial commodity), to provide power, heat, electricity, etc., and we can’t imagine life without it. Several kinds of fuels are available in the market, mainly non-renewables – fossil based (coal, crude oil, etc.). However, due to awareness about long-term issues related to use of fossil fuels, several other types of renewable fuels are gaining much attention. Biogas, biofuels (bioethanol, biodiesel), and biohydrogen are some of the examples for such renewables with very high future potential. However, even with those recent developments, rural areas in some of the developing countries are still using agricultural remains, cow dung, etc., for cooking and heating purposes. This kind of crude practice significantly raises environmental, economic, and public health-related worries. To achieve a worldwide sustainable progress in both developed and developing countries, clean and affordable energy could be offered by using the existing biomass resources (crop residues, agro-industrial, animal, and other type of wastes) to produce a cleaner, more efficient, and reliable energy, such as biogas. Unlike other types of renewable biofuels, biogas production is a natural non-energy intensive process, and the raw materials are mostly renewable resource and wastes – thus serving both purposes, bioremediation and energy generation. Biogas is a blend of gases, mainly methane and carbon dioxide. Over the years, several biogas plant designs are available, which are compiled in present chapter along with its advantages and disadvantages. At present several countries are already utilizing biogas for various household and industrial applications. The main applications are generating electricity, cooking, heating, and using as a fuel for transportation. The ease of operation, maintenance, and easy availability of substrate – waste materials – are some of the key selling points for biogas to be an effective and common energy tool in the near future.