Bacteria eat CO2 to store energy
Published 06 April, 2009, 11:32
A bacterium that can use electric current to convert carbon dioxide into natural gas may make renewable energy more reliable.
One of the major problems with alternative energy supplies like solar and wind power plants, compared to those using fossil fuels, is that their supply is not reliable. If the wind dies down or the sky is overcast, the power drops, which can potentially lead to a blackout.
The obvious solution is to store surplus energy when it’s abundant so that you have reserves in times of need, but then problems arise of how exactly one should stockpile it.
An elegant and promising solution comes from a team of researchers at Pennsylvania State University, reports the Science magazine. They suggest feeding extra electricity to bacteria, which can use it to convert carbon dioxide into methane.
The team headed by Bruce Logan discovered this behaviour in a mixed culture of bacteria dominated by Methanobacterium palustre.
Methane may later be burnt just like fossil natural gas to take back the stored energy. If the CO2 used in the process is taken from power stations or directly from the atmosphere, it will be carbon neutral and not contribute to climate change.
Logan, who also studies microbial technology to produce electricity from organic waste and to produce hydrogen, says this method is just years from practical use.
He said: “Hydrogen doesn't fit into our existing infrastructure. Methane does.”
Bioenergy is an attractive field of research for many scientists. Microbes have been used to produce drugs for decades, but it’s only now that we try to incorporate them into the energy industry, be it methane-based storage or algae-based generation.
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