Co-Generation System of Bioethanol and Electricity with Microbial Fuel Cell Technology

A co-generation system of bioethanol and electricity using a yeast microbial fuel cell was investigated. The co-generation system was found to have a high power output (5.2 +/- 0.5 W/m (3)) and high ethanol yield (92.5 +/- 2%) when traces of methylene blue (MB) (6.25 mg/L) were added. The color change of the anolyte was recorded confirming the electron transfer mechanisms in the presence of MB. In repeated batch operations, the co-generation system helped to realize yeast cell recycle. No fresh yeast was needed to be added between batches, and the co-generation system could be maintained giving a stable voltage of around 350 mV and an ethanol yield of around 90% of the theoretical yield in 96 h. The co-generation system has potential application in industrial fermentation, thus making not only a full use of the substrate for biochemical production but also producing clean energy, that is, electricity.