Chemical engineers at UC Berkeley have created a new, cleaner fuel out of an old concoction that was once used to make explosives. The fuel, which uses a century-old fermentation process to transform plant material into a propellant, could eventually replace gasoline and drastically cut down on greenhouse gas emissions, according to the team of Berkeley scientists. The discovery, published in the journal Nature, means corn, sugar cane, grasses and other fast-growing plants or trees, like eucalyptus, could be used to make the propellant, replacing oil. The research into creating a diesel substitute is part of a 10-year development program by the Energy Biosciences Institute, a collaboration among UC Berkeley, Lawrence Berkeley National Laboratory and the University of Illinois at Urbana-Champaign. The research, paid for using $50 million a year from the British oil company BP, has been going on for five years. [The researchers] extracted the acetone and butanol from the fermentation mixture [and] then created a catalyst that converted the brew into a mix of hydrocarbons similar to those in diesel fuel. The resulting substance burns as well as petroleum-based fuel and contains more energy per gallon than ethanol, according to the study. It can be produced using a variety of renewable starches and sugars that can be grown in crops. The expectation in California is that it will be used initially for niche markets, like the military, and eventually in trucks, trains and other vehicles that need more oomph than hybrid or battery power can provide.