High energy liquid fuel created from sugar

Madison, Va. -- U.S. scientists have transformed sugar into a liquid transportation fuel they say has a 40 percent greater energy density than ethanol.

Reporting in the journal Nature, University of Wisconsin-Madison Professor James Dumesic and colleagues describe a two-stage process for turning biomass-derived sugar into 2,5-dimethylfuran, or DMF.

"Currently, ethanol is the only renewable liquid fuel produced on a large scale," said Dumesic. "But ethanol ... has relatively low energy density, evaporates readily, and can become contaminated by absorption of water from the atmosphere. It also requires an energy-intensive distillation process to separate the fuel from water."

Not only does dimethylfuran have higher energy content, Dumesic said it also is not soluble in water and therefore cannot become contaminated by absorbing water from the atmosphere.

DMF is stable in storage and, in the evaporation stage of its production, consumes one-third of the energy required to evaporate a solution of ethanol produced by fermentation for biofuel applications, he added.

Dumesic and graduate students Yuriy Roman-Leshkov, Christopher Barrett and Zhen Liu also describe an improved process for turning sugar into a chemical intermediate -- hydroxymethylfurfural -- in the journal Science.

Copyright 2007 by United Press International.