Fermentation of sugars to ethanol, using commercially available fermenta­tion technology, provides a fairly simple, straightforward means of produc­ing ethanol with little technological risk. The system modeled assumes that the molasses is clarified, and then fermented via cascade fermentation with a yeast recycle. The stillage is concentrated by multiple-effect evaporation and a molecular sieve is used to dehydrate the ethanol. Corn ethanol is com­mercially produced in one of two ways, using either the wet mill or dry mill process. The wet milling process involves separating the grain kernel into its component parts (germ, fiber, protein, and starch) prior to yeast fermenta­tion. On the other hand, ICM-designed plants utilize the dry milling process, where the entire grain kernel is ground into flour form first. The starch in the flour is converted to ethanol during the fermentation process, also creating carbon dioxide and distillers grain as principal by-products.