Fruit sugar could fuel autos
MILWAUKEE – A simple sugar found in fruit and a variety of other sources could be converted to fuel for cars and trucks.
University of Wisconsin-Madison researchers said Thursday they have found a better way of converting fructose, a common sugar, into a fuel called 2,5-dimethylfuran, or DMF.
The biofuel has a higher energy content than ethanol, currently the only renewable liquid fuel produced on a large scale. It also doesn’t absorb water from the atmosphere, which is a shortcoming of ethanol, said James Dumesic, one of the researchers and a professor of chemical and biological engineering at the university.
Concern over diminishing oil reserves and the threat of global warming caused by burning fossil fuels have scientists searching for alternative energy sources. By chemically engineering sugar through a series of steps involving acid and copper catalysts, salt and butanol as a solvent, the researchers have created a path toward what could be a better fuel.
Their results were reported Thursday in Nature, a prestigious scientific journal.
“Optimistically we might be just a couple of years away. It’s a two-step process to convert the fructose into DMF, but the two steps are very similar to the processes already used in the petroleum industry,” Dumesic said in an interview.
Researchers are gearing up to produce DMF in larger quantities for testing in gasoline engines.
“The main concern I would have about getting too exuberant is we really don’t know the environmental toxicological factors associated with the widespread use of DMF,” Dumesic said. “We think it’s very important to have experts other than ourselves really make sure that widespread use of this fuel would, in fact, be safe for the environment and for people.”
The research shows that a biofuel can have the same energy density as petroleum, which is important in finding alternatives to fossil fuels.
But DMF won’t necessarily replace ethanol, at least not in the near future.
Ethanol and DMF could be made from the simple sugars found in renewable energy sources such as paper-mill waste.
Apples and oranges could be another fuel source.
“But I think fruit would be a very small supply,” Dumesic said.
The UW-Madison approach “heralds the advent of a second generation of biofuels,” Lanny Schmidt and Paul Dauenhauer, professors of chemical engineering and material sciences at the University of Minnesota, wrote in a peer review of the research.
This is a “ground-breaking example of interdisciplinary engineering that may well dictate the future of biomass conversion,” the researchers noted.
But investors in ethanol plants aren’t necessarily worried that DMF will become a competing fuel.
The research is a “moot point” until there’s a cost-effective way to convert biomass into sugar, said James Hanke, director of Badger AgVest LLC, a group that encourages biofuel investments.