With so much interest in renewable fuels, many methods of creating them are being developed; far more than may ever be used for commercial purposes. Many of the methods for creating biofuels by converting CO2 into another compound rely on photosynthesis within an organism to take the CO2 and make fuel for itself. This fuel is then converted for human use. While the entire process is fairly clean, it is not very efficient. Energy is lost because of second step using photosynthesis. Researchers at Berkeley Lab are working on a more efficient system that creates electrofuels, instead of biofuels.
Electrofuels are chemically the same as biofuels, but are made differently. Instead of using the energy from sunlight to create a fuel for the organism, the researchers are using a bacterium called Ralstonia eutropha to directly convert CO2 into a fuel. By removing the photosynthesis step, systems to produce electrofuels could be ten times more efficient than current biofuel production systems.
Naturally there is more research to do before we find electrofuels at the pump, but then the same is largely true of biofuels. Either way, the technology should eventually provide a means to recycle CO2 already in the atmosphere, as opposed to just releasing more of the gas.