Lincolnland Agri-Energy, LLC
Dried Distillers Grains
News & Commentary
The Lincolnland Agri-Energy, LLC Ethanol Process
Corn arrives by semi-truck and railcar. The corn is unloaded and stored in the double silo that can hold 400,000 bushels of corn or in one of the three bins that have a combined capacity to hold 2,100,000 bushels. Hammermills grind the corn into a coarse flour. When water and an enzyme are added to the flour, a slurry mash is formed. The enzyme breaks down the starch in the flour into complex sugars. The slurry mash enters a fermentation tank where yeast and a second enzyme are added. This enzyme breaks the complex sugars into glucose, the simplest form of sugar. The yeast convert the glucose into alcohol and carbon dioxide. At this point the mash is called beer. The beer is sent to distillation where the alcohol is heated and separates from the beer. The beer, now that the alcohol is removed, is called whole sillage and is pumped to the centrifuges where centrifugal force is used to separate the liquid from the solids. The liquid, called thin sillage, is condensed by boiling and is called syrup.
The solids, called wetcake, are sent on conveyors to the dryers where most of the moisture is removed. Two forms of wetcake are produced: Dried Distillers Grains with Solubles (DDGS) and Modified Distillers Wet Grains with Solubles (MDWGS).
DDGS is has a low moisture content and can be stored for a long period of time. It is sent by railcar and semi-truck throughout the country and is fed predominately to cows, pigs and poultry. The MDWGS is dried wetcake with some of the syrup that was removed earlier in the process added to it. MDWGS is fed to local livestock since the addition of the syrup, while increasing the moisture content, decreases the shelf life.
The alcohol that was removed is boiled and concentrated to 190 proof then sent to molecular sieves where the water molecules become trapped and are removed. The alcohol is now 200 proof. A small amount of denaturant is added to the 200 proof alcohol to make it unfit for human consumption. Denaturant is natural gasoline that contains no additives. The alcohol, now called ethanol, is pumped to holding tanks.
Semi-trucks and railcars are loaded with ethanol and sent across the United States. The ethanol is blended with gasoline and sold at gas stations. Many gas stations offer a blend of 10% ethanol and 90% gasoline. A blend of 85% ethanol and 15% gasoline, called E-85, is also available to consumers.