Confusion Over Biofuels

In his letter to the editor, John Burton points out that considerable confusion still exists among experts as to whether or not biofuels, such as ethanol from corn, consume more energy in their production than they contain as fuel (C&EN, March 3, page 3). The same subject was previously debated in the excellent article "The Cost of Biofuels" by Bruce E. Dale and David Pimentel (C&EN, Dec. 17, 2007, page 12).

The above-cited articles certainly raise and debate important issues. However, I would like to point out a few fundamental factors in favor of biofuels that have not been emphasized and that probably are more important than the energy balance of biofuels.

First, the key reason for considering biofuels for automotive use is that current automotive technology requires liquid fuels of high volumetric and mass energy density (high calories per cubic centimeter and high calories per gram), similar to that of petroleum-based liquids like gasoline and diesel oil. The reason is that cars have to meet strong space and weight constraints in order to be practical. Biofuels such as ethanol and biodiesel meet these requirements without requiring significant engine modifications.

Second, even if it turns out that biofuels consume somewhat more energy in their production than they contain as fuel, this is not a big problem because the energy required can easily be supplied by nonpolluting sources such as nuclear energy, hydro-electric power, solar power, and wind energy. In time, enough of these clean-energy resources will be available to replace fossil-fuel-fired power plants. In such a system, there will be no net global warming effect because the biofuels are carbon-neutral and the synthesis energy does not produce any CO₂.

Third, biofuels will not encounter a critical cost deterrent because the past few years have shown that automotive fuel is a highly price-inelastic commodity—that is, consumption is not price-sensitive within certain limits.

Oswald R. Bergmann
Wilmington, Del.