Researchers at the University of Wisconsin-Madison have a paper in the article in today's Nature about making the higher-energy liquid-transportation fuel from, basically, fruit juice.
The two-stage process is the work of chemical and biological engineering Professor James Dumesic and his research team. Using acid and copper catalysts, salt and butanol solvents
In a UWM press release, Dumesic explains ethanol's shortcomings: "Ethanol suffers from several limitations. It 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."
DMF, by comparison, is not soluble in water, can be stored stably and uses just one-third of the energy in the evaporation process compared to ethanol produced by fermentation. This fruit-juice biofuel is not exactly ready for the highway quite yet, and Dumesic says there is more research to be done, but if Daryl Hannah wants to keep drinking biofuels, perhaps she'll like the sweeter variety.
[Source: University of Wisconsin / James Beal via Australian Car Advice]