Climate change is one of the main challenges that we currently face. In 2015 the average concentration of carbon dioxide (CO2), the main greenhouse gas, exceeded 400 parts per million (ppm) for the first time: a symbolic barrier that urges us to find technological solutions to revert this steady growth. Palliative measures such as carbon capture and storing are controversial. By contrast, the development of alternatives to the burning of fossil fuels gets to the root of the problem and proposes substantial changes to energy and industrial systems.
This is the case with bioelectrochemical systems (BES), an emerging technology that combines biological and electrochemical processes, and that has arose great interest among the international scientific community during the past ten years. BES are based on the capacity of certain microorganisms to facilitate oxidation/reduction processes through the release/capture of electrons from an electrode. Thus, BES could reduce carbon dioxide to biofuels (e.g. methane) or to other high added value products, and tackle climate change and energy challenges from an integrated approach.
Pau Batlle Vilanova’s doctoral thesis confirms that BES are promising technologies to reduce and convert CO2emissions. The researcher studied different bacteria able to use the electrode as electron donor (biocathode) and carry out the reduction of carbon dioxide. Results demonstrate that hydrogen production at laboratory scale as an intermediate product is crucial. Obtaining hydrogen in situ would mean a competitive advantage, as the need for transport and storage would be eliminated. Regarding the final products, Pau Batlle has synthetised methane (that can be used as fuel for transportation or fed into the grid) and liquid organic compounds of two (acetic acid) and four (butyric acid) carbons. Both compounds are used by the food and the pharmaceutical industry, and are precursors of two important biofuels, ethanol and butanol. Therefore, the results invite us to continue investigating in order to exploit all the potential of BES to reduce CO2 and making it industrial scalability feasible.