Promising Biofuel from New Extraction Process.

• Position: ETHANOL SUBSTITUTE

Taking a step closer to a "green" replacement for fossil fuels, a research team that includes a chemical engineer at Worcester (Mass.) Polytechnic Institute has developed a novel process using an unusual solvent and an exotic microorganism that may make it possible to manufacture isobutanol and other biofuels more economically.

Isobutanol, like ethanol, is an alcohol, but its lower water solubility (which reduces the risk of corrosion associated with many biofuels) and higher energy density (which translates to increased miles per gallon) have created considerable interest in the compound's potential use as a gasoline additive and even a gasoline replacement.

However, isobutanol is made in a bioreactor by fermenting biomass using microorganisms. The final product is extracted with organic solvents, which often are flammable, toxic, and costly.

"With the growing threat of climate change and our dependence on fossil fuels and petroleum-producing countries, there is increasing interest in using isobutanol as a gasoline additive in place of ethanol, which can significantly lower a vehicle's fuel efficiency but we haven't found an environmentally friendly, efficient, or inexpensive way...