The Economist: One for the Road
A new biofuel made from fruit sugars promises more oomph than traditional ethanol.
.... By their very nature, biofuels cannot be carbon-free because carbon is essential to life on Earth. Burning biofuels does indeed release carbon dioxide, a greenhouse gas. The attraction is that the volume of gas released exactly matches that taken up by the plant when it was growing. So overall (and with the huge proviso that you do not count the fossil fuel used to farm the stuff) biofuels are carbon-neutral.
In America the Department of Energy has set a target for 30% of the 2004 gasoline demand for vehicles to be met by biofuels by 2030. The European Union wants 25% of transport fuels to be derived from biofuels by the same date. At present, the most widely used substance is ethanol, which can be made from sugar cane, sugar beet and maize (or corn, as it is called in America). But ethanol does not pack a particularly powerful punch. It is also susceptible to absorbing water, further diluting its oomph. It takes days to ferment the stuff. A biofuel that did not suffer from these limitations would be welcome.
That is what a team led by James Dumesic of the University of Wisconsin-Madison claims to have developed. The researchers think they have devised a biofuel that has a 40% higher energy density than ethanol, that repels water and that can be made relatively speedily.