Biogas upgrading technologies – Recent advances in membrane-based processes

This study reviews the major biogas upgrading technologies, with specific regard to recent progress in the field of membrane technology. More specifically, the objective of the present work is to provide the state-of-the-art of membrane-based processes for biogas upgrading, focusing primarily on the latest advances in membrane configurations/materials (e.g. for producing novel composite or mixed matrix membranes) and on hybrid technologies which integrate biogas upgrading with established membrane-based processes, such as the membrane bioreactor, membrane electrolysis or gas-liquid absorption. In order to demonstrate the potential of membrane technology for biogas upgrading in real field applications, the review also presents some cutting-edge biogas upgrading plants, located and operated in Europe and USA, and a brief summary of recent research studies (conducted during the last 5 years), which examine the economic feasibility of membrane-based technologies for biogas upgrading. Finally, challenges and future perspectives of applying membrane-based processes for biogas upgrading are discussed.