Bioelectrochemistry of Microbial Fuel Cells and their Potential Applications in Bioenergy

The world's oil supplies are dwindling. Bioenergy is an integral part of renewable energy solutions to relieve the current energy crisis. Unlike liquid biofuels such as bioethanol and biodiesel, microbial fuel cells (MFCs) generate electricity directly by degrading organic matter through electrochemical reactions. MFCs are capable of utilizing low-grade organic matter in wastewater streams. Despite the numerous theoretical advantages that MFCs have, they are not yet ready for “real-world” applications other than powering small sensor devices because of their low power output and high costs in construction and operation. New advances are needed in biofilm engineering, materials for electrodes and reactor configuration to achieve much better bioelectrochemical performance. This chapter reviews the bioelectrochemistry of electrogenic biofilms and the electrochemical mechanisms of MFCs. It explores various ways to improve MFC performance including state-of-the-art hypotheses on using engineered biofilms to revolutionize MFCs.