Earless corn could impact U.S. ethanol

A University of Illinois scientist is teaching an old plant some new tricks that could have revolutionary impact on the ethanol industry in the U.S.

Fred Below, professor of plant physiology, began growing tropical maize near the University of Illinois Urbana-Champaign more than two decades ago to study the genes involved in the plant's use of nitrogen. But it wasn't until recently that the plant became appealing for a different reason.

Tropical maize stores simple sugars in its stalk rather than growing ears. This sugar is easier to process into ethanol than traditional corn.

Corn ethanol production methods require breaking down cornstarch into simple sugars, which are then fermented into ethanol. Since tropical maize already stores its energy in the form of simple sugar, this intermediary step is unnecessary.

The result is a plant similar to sugarcane, which also stores sugars in its stalk and is a source of cheap ethanol.

According to studies performed by Michael Wang at Argonne National Laboratory, one unit of energy output from gasoline requires 1.2 units of energy input when all aspects of gasoline production are taken into account.

One unit of energy output from corn ethanol, on the other hand, only requires .74 units of energy input. Sugarcane ethanol is about four times as efficient as corn ethanol.

Unfortunately, sugarcane can't be grown in the Midwest climate, and steep tariffs effectively bar Brazilian sugarcane ethanol from entry into the U.S. market. Tropical maize, however, could provide a viable alternative to sugarcane for cheap and efficient ethanol.

The plant has other benefits over traditional corn.

Corn requires a tremendous amount of nitrogen fertilizer, which runs off into streams and other water sources and wreaks havoc on the environment. Tropical maize, since it doesn't produce ears, requires less fertilizer.

"Fertilizing corn is about making grain, and if you're not about making grain and you're making sugar instead you need a lot less (nitrogen)," Below said.

Tropical maize is also attractive because it could be harvested with the same equipment already in use to harvest traditional corn, unlike other potential sources of biofuel. The plant can also be easily rotated with traditional corn or soybeans. If a farmer doesn't like it, he can plant a different crop next year.

"What we're saying is you don't need a new crop for biofuel, we've got it right under our noses," Below said.

Hans Blaschek, director of the Center for Advanced BioEnergy Research at the university, is looking into the potential commercial aspects of tropical maize ethanol.

"The wow factor could be huge," Blaschek said.

Sugar extraction from tropical maize is such a new process that more testing is needed to determine whether it can support the organisms necessary for ethanol production, Blaschek said.

But since announcing the implications of tropical maize on the university Web site a few days ago,Blaschek says it has elicited a "large amount of interest" from the ethanol industry.