German Company Fills Tanks with Sun

Fuel is simply chemically converted solar energy. Through the photosynthesis in plants, sunlight can be converted into fossil energy, such as coal and oil.

It's a principle which a resourceful tinkerer in Saxony thought must be easy to copy. In 1990, it was still a vision. Today, the company Choren in the Saxon town of Freiberg actually produces synthetic fuel from biomass, or plants of all kind.

"The biomass goes into a multiple-stage gasification process, which undergoes the various chemical processes until it is a high-purity synthesized gas," said managing director Carlhans Uhle. "This gas in turn is converted into diesel through several processes."

Choren calls its product SunDiesel. The technical term is biomass to liquids, or BTL. Four kilograms of biomass, for example wood, become one liter of diesel. But while fossil fuels developed over a period of some 400 million years, this process only takes 400 minutes in Freiberg.

"If you also consider the time it takes the plants to grow, then it's around 400 days," Uhle said.

A closed energy cycle

Choren obtains the raw material for production from local farmers, Saxon's state forestry and sawmills. Since it doesn't just use the plant fruit, but rather the entire plant, the output per hectare of cultivable land in BTL in comparison to normal biodiesel is three to four times higher.

"We can take any biomass we want to," Uhle said. "Nothing negative is left over, except for a bit of slag, which can be used to tar floors. We are a closed energy cycle." In view of the ongoing climate debate, this aspect was particularly important.

When this fuel is burned, it releases only as much carbon dioxide previously absorbed by the plants produced for this purpose. The fuel also contains no sooty particles and can be filled into any diesel engine without re-fitting.

Biomass fuel can be competitive

SunDiesel is still in the testing phase. Only a few hundred liters are produced daily. But large automobile producers, such as DaimlerChrysler and Volkswagen, and the energy giant Shell are already on board. Together with Choren, they are building a commercial facility, which will take up operations in the coming year and produce 250 million liters (66 million gallons) annually. Four further facilities are planned.

"Our technicians' forecasts say that we are at a stage with the large scale plant to be competitive," Uhle said. "Of course, it always depends on the oil price and the dollar."

With the current high oil prices, the fuel will definitely be competitive with the construction of the third facility in 2012 or 2013 -- and that without further subsidies.

A liter of SunDiesel still costs double that of diesel from petroleum. The production costs are high and each new plant requires 400 million euros ($515.8 million) in investments. Still, BTL is sparking interest worldwide; Choren has had inquiries from all over Europe, the United States and China.