Scientists use tiny organisms to create fuel, viruses to make batteries.
For millenniums, microbes have been a staunch technological ally. They have leavened our bread and cured our cheeses. Now, engineers are asking them to convert carbon dioxide into fuel and to build a new generation of batteries. Some of the smallest life forms with which we share the planet are helping us cope with the energy challenges of the 21st century.
Forget about the so-called hydrogen economy for a moment. The much-discussed plan to use hydrogen as a major power source has serious problems, such as how to deliver the fuel to consumers.
Bruce Logan at Penn State says methane could be a much more appealing candidate. Through the study of how microbes produce methane in swamps, bogs, and landfills, he and his colleagues believe they have found a perfect source for the gas.
They found certain microbes that use electricity to convert CO2 and water into methane. These hydrolysis cells convert electrical energy into energy stored in methane with 80 percent efficiency.
Technical details of this research appeared in the journal Environmental Science and Technology, and Professor Logan emphasized the potential environmental benefits in a separate statement. No extra carbon has to be added to make methane, he writes. When the gas is burned for fuel, it only lets off as much CO2 as originally went in, saving utilities from pumping more greenhouse gases into the environment. Furthermore, if the electricity used in the process comes from solar or wind power, the entire fuel cycle would not add any extra CO2 to the environment.