The Corn and soybean Digest
10-01-06
It's Not Moonshine Anymore
By Susan Winsor
It may soon cost just a penny a gallon to add a lot of value to a gallon of ethanol.
Two Iowa State engineers have invented a process that reduces the cost of
purifying ethanol into food-grade alcohol by 98%.
Removing organic impurities from ethanol is not such a departure from the
professions of these two inventors. Jacek Koziel and Hans Van Leeuwen use
these same technologies to remove ag compounds from air and wastewater.
Koziel is assistant professor of Air Quality Engineering and Livestock Odor
at Iowa State University. His partner in this venture is Hans Van Leeuwen,
Iowa State professor of Civil, Construction and Environmental Engineering
and vice president of Mell03z, a Cedar Rapids startup firm. The firm holds two
patents that improve the quality of alcoholic liquors.
“We use ozone to oxidize undesirable compounds, and then filter the ethanol
with granular activated carbon filters,” says Van Leeuwen. He's already used the
process to purify wastewater successfully. This uses a small fraction of the
energy required by multiple distillations, the conventional purification process.
Although ethanol and alcoholic spirits are chemical twins, the latter result from
multiple distillations to catch impurities contaminating taste and smell. The
colorful part of this research is the “sniff board” used to quantify things like the
rotten egg smell. For example, sulfur-based compounds in fuel ethanol often
impart a “barnyard smell and taste,” says Koziel. These mercaptan compounds
resemble the rotten-egg smell added to natural gas as a tracer. “There are low
levels of sulfur in all plant material, so this isn't surprising,” he adds.
The U.S. market for food-grade alcohol is 250 million gallons annually, says Van
Leeuwen. This is small compared to the 4.6 billion gallons of ethanol produced
annually in the U.S., but represents another market for farm crops. The
professors' new technology would be inexpensive to retrofit on existing ethanol
plants, he says.
Adding value to farm crops was the basis of Koziel's original $79,900 grant from
Iowa's Grow Iowa Value fund.
The daunting terminology is actually straightforward to grasp. Bubbles of ozone
gas burn off (oxidize) undesirable compounds, and combine with others to be
screened out by the carbon filter. The degree and combination of these two
processes is the essence of their patent.
While the technology is relatively simple, the regulatory hurdles involved in foodgrade alcohol are not. Spirits manufacturing requires a higher standard of
purification, and of capital investment, says Nathan Fields, National Corn
Growers Association director of research and business development. “If these
researchers can reduce the cost to 1¢/gal., it would be a great way ethanol
producers can add value,” he says.
Koziel and Van Leeuwen have been approached by a few large alcohol
companies interested in their new experimental process.
Midwestern Vodka
One ethanol plant that has cleared the bonding and regulatory hurdles of foodgrade alcohol production is the Chippewa Valley Ethanol Co., Benson, MN. Its
wholly owned subsidiary, Glacial Grain Spirits, produces Shakers Vodka. Its fuel
ethanol is made from corn, but its vodka is distilled from wheat and rye.
The continuous distillation process is powered by natural gas, and general
manager Bill Lee finds the potential alternative interesting. “The vodka is a small
percentage of what we do, yet it would be very significant if we could reduce
ethanol purification costs by the magnitude delivered by the Iowans' new
technology,” he says.
The 45-million gallon ethanol cooperative began 10 years ago. It's the only
farmer-owned ethanol company in the beverage business.