The growth of the fuel ethanol industry in the US has been
significant, with 1.6 million gallons produced in 2000 and 10.7
million gallons by the end of the decade in 2009 [1]. The vast
majority of ethanol is currently produced by the dry milling of
corn, and every bushel of corn creates 2.7 gallons of ethanol
and 16 pounds of a fermentation residue product known as
distiller’s dry grains with solubles (DDGS) [2]. While the
highest value and societally most important application of
DDGS is as an animal feed, an issue confronting manufacturers
concerns the treatment of products obtained once the
ethanol has been removed from the fermentation media in
the beer well. The resulting liquid/solid mixture is centrifuged
to obtain wet distiller’s grains (WDG) having a moisture
content of 65e70% [3] and a thin stillage supernatant having
a moisture content of 90e95% [4]. Both of these materials are
generally intermediate products and require significant