**Abstract**

Biogas is a renewable energy resource derived from biomass mainly through anaerobic digestion. Methane (CH4) and carbon dioxide (CO2) and trace elements significantly affect the fuel. Hence, the undesirable components are undesirable and should be removed for various biogas applications. This makes it necessary to purify raw biogas to increase its utility making it suitable for many applications as a sustainable energy resource and process feedstock. Biogas can make substantial contribution to realization of sustainable development goals and the global energy transition. However, the wide-scale use of biogas is seriously constrained by the presence of harmful impurities as well as the low calorific value of biogas. The overall objective of this chapter is to investigate the properties of biogas, its cleaning, upgrading, and its sustainability as a transition energy resource for realization of sustainable development goals and the global energy transition. The chapter provides a comprehensive examination of the potential of biogas as a fuel and potential feedstock for various industrial processes. Furthermore, this study offers a comprehensive examination of the various technological alternatives that can be employed to harness biogas for the purpose of generating heat and electricity.

**Keywords:** raw biogas, biogas properties, biogas applications, energy potential of biogas, sustainability of biogas fuel, electricity from biogas, biogas reforming, liquid biofuels, Fischer-Tropsch
