• Universitat de València

• Raúl Rodriguez Barreiro 
• Cristina Vilanova Serrador 
• Christian Abendroth 

One of the main problems facing society today is the huge global growth in energy demand. Alternative non-fossil and non-nuclear technologies are seen as promising energy sources, although they are not yet fully competitive. There are microbiological systems that allow the direct conversion of biomass into electricity using electrogenic bacteria - which produce electrons by oxidising organic matter. These devices are known as microbial fuel cells (generically referred to as MFCs, or Microbial Fuel Cells). Energy efficiency in MFC technology has increased dramatically in recent years, mainly by increasing the ratio of electrode area to reactor volume, but the most effective results obtained in such technologies have been on a small scale (in devices with volumes of less than 1 litre). Therefore, there is a need to develop technological improvements in procedures for obtaining electrical energy from microbiological cultures.

Researchers from de Universitat de Valencia have proved the production of electric energy from cultures of exothermic micro-organims using the thermo-electric effect, in other words, by converting the heat produced as a result of microbial growth into electrical energy. Furthermore, they have developed the necessary device to achieve this energy transformation efficiently. This conversion of the heat produced by the growth of exothermic microbial cultures into electricity allows the design of electrical energy to produce devices that can be coupled to different types of microbial reactors. Furthermore, it is possible to obtain means of energy production that can be incorporated into the future development of microbiologically based cellular electrical installations, which could be useful for local electricity production and heat recycling from a wide range of microbiological processes.

The main application of the technology is in the biotechnology sector, for the production of electrical energy from the growth of microbial cultures in different applications such as alcoholic fermentation, bioremediation, waste treatment, autotrophic aerobic thermal digestion, etc.

The main advantages provided by the invention are:

• Use of an undesirable by-product such as the metabolic heat of microbial fermentations.
• Greater survival of the culture as this procedure allows the internal temperature of the microbiological process to be controlled.
• Universality, the procedure is applicable to any exothermic culture.

• Patent granted