Electricity and hydrogen production using different types of microbial fuel cell technologies

Virtually any form of biodegradable organic matter can be used to produce electricity in a microbial fuel cell (MFC), including carbohydrates such as glucose, starch, fatty acids, amino acids, and proteins. The process can also be used with animal and human wastewaters, resulting in both electricity generation and wastewater treatment method. A study on the effect of solution ionic strength, electrode spacing, and temperature on electricity generation using a single chamber, membrane-free MFC was carried out. By using a completely anaerobic system, hydrogen could be produced from fermentation end products if the electrochemical potential achieved by bacteria is augmented using an external power source. This makes it possible to produce hydrogen directly from the oxidized organic matter. This MFC adapted process is called a bio-electrochemically assisted microbial reactor (BEAMR). Using the BEAMR process, acetate was converted to hydrogen by augmenting the electrochemical potential achieved by bacteria to produce hydrogen directly from the oxidized organic matter. This bio-electrochemically assisted process, if combined with hydrogen fermentation, has the potential to produce 8-9 mole-H₂/mole glucose at an energy cost equivalent of 1.2 mole-H₂/mole-glucose. This is an abstract of a paper presented ACS Fuel Chemistry Meeting (Washington, DC Fall 2005).