Microbial Fuel Cells (MFCs) - a novel source of energy for new millennium

Continued use of petroleum fuels is now widely recognized as unsustainable because of their depleting supplies and the contribution of these fuels to the accumulation of carbon dioxide in the environment. Renewable, carbon neutral, transport fuels are necessary for environmental and economic sustainability. A microbial fuel cell (MFC), a novel form of microbial respiration has recently been discovered, it is a bioreactor that converts chemical energy present in the organic compounds (in the form of chemical bonds) to electrical energy through catalytic reactions of microorganisms under anaerobic conditions. These organisms, termed electricigens, Microbial fuel cells (MFCs) provide new opportunities for the sustainable production of energy from biodegradable compounds. MFCs function on different carbohydrates and also on complex substrates present in wastewaters and renewable biomass. Biomass, especially organic waste, is being considered as a valuable candidate. The use of biomass, in the case of waste organics, is environment friendly and regarded as a renewable energy source. The construction and analysis of MFCs requires knowledge at both scientific and engineering fields, ranging from microbiology and electrochemistry to materials and environmental engineering. Therefore unfolding MFC systems involves an understanding of these diverse scientific and engineering principles. At present, microbial fuel cells are not commonly considered a part of the energy portfolio for the future, is that microbial fuel technology is not yet sufficiently well developed to produce substantial quantities of power in a cost-effective manner. In this chapter, we provide a review of the different materials and methods used to construct MFCs, techniques used to analyse system performance, and recommendations on what information to include in MFC studies in the new millennium.