Organic fuel cells can turn methane into electricity without harmful leaks

fuel cell
A team of researchers crafted microbial fuel cells that can convert methane into electricity right at the well, without leaking loads of gas into the atmosphere by sending it through pipes.
The team created a cocktail of bacteria that produces the necessary materials to grab and transport electrons from the methane. Not only is this a relatively clean process, the bacteria can run on waste products it might clean up the site as it generates power.

Chemical Engineering professor explains

Thomas K. Wood, professor of chemical engineering, Penn State, said, Microbial fuel cells convert chemical energy to electrical energy using microorganisms. They can run on most organic material, including wastewater, acetate and brewing waste. However, Methane causes some problems for microbial fuel cells because, while there are bacteria that consume methane, they live in the depths of the ocean and are not currently cultural in the laboratory.
The researchers actually created a consortium of bacteria that produces electricity because each bacterium does its portion of the job. Using synthetic biological approaches, the researchers created a bacterium like those in the depths of the Black Sea, but one they can grow in the laboratory.
The researchers also added a mixture of bacteria found in sludge from an anaerobic digester the last step in waste treatment. This sludge contains bacteria that produce compounds that can transport electrons to an electrode, but these bacteria needed to be acclimated to methane to survive in the fuel cell.
Once electrons reach an electrode, the flow of electrons produces electricity. To increase the amount of electricity produced, the researchers used a naturally occurring bacterial genus Geobacter, which consumes the acetate created by the synthetic bacteria that captures methane to produce electrons.
To show that an electron shuttle was necessary, the researchers ran the fuel cell with only the synthetic bacteria and Geobacter. The fuel cell produced no electricity.
They added humic acids a non-living electron shuttle and the fuel cells worked. Bacteria from the sludge are better shuttles than humic acids because they are self-sustaining. The researchers have filed provisional patents on this process.
Wood said, this process makes a lot of electricity for a microbial fuel cell. However, at this point that amount is 1,000 times less than the electricity produced by a methanol fuel cell.
More information: [Nature]
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