Ethanol Process

WPE can store up to 1.8M bushels of grain. All grain is received by truck, and is then stored until it is processed.

Grain is milled into a flour and then mixed with water and enzymes. The enzymes help to break down the starch that is present in the grain into sugar molecules.

During the fermentation process, yeast metabolize sugar molecules into ethanol and carbon dioxide. This process typically takes 60 hours to complete, and results in a liquid product that we call beer that contains about 14 w/v% alcohol.

The beer from the fermentation step is pumped to the distillation system where the ethanol is stripped away from the water and non-starch components of the grain. The ethanol stream leaving distillation is 190 proof, which is 95% pure ethanol.

To further concentrate the ethanol up 200 proof (99.5%+ ethanol), we use molecular sieves which trap water molecules and allow pure ethanol molecules to pass through.

WPE has 2 large storage tanks to store product in until it is shipped out by truck or by rail.

Fuel-grade ethanol is 200 proof ethanol that has been denatured with approximately 2.5% gasoline. This product is sold to fuel blenders to be blended down to E10 (i.e. 10% ethanol, 90% gasoline) or E15 (i.e. 15% ethanol, 85% gasoline) before it is shipped to gas stations.

The water and non-fermentable (i.e. oil, protein, fiber) portions of the grain are separated by large centrifuges.

Wet Distiller's Grains (also called WDG, WDGS, and Wet Cake) is a high-protein, high-energy animal feed product. The product from WPE is predominately fed to beef and dairy cow operations within our geographical region.

The production from WPE is pre-dominantly fed to beef and dairy cow operations within our geographical region. See the distiller's section on this webpage for more detailed nutritional information.

Evaporation is used to further concentrate the liquid stream from the centrifugation process. The resulting product is called syrup and is around 32%-34% solids.

A distillers dryer is used to convert the wet distiller's grains (65-67% moisture) to dry distiller's grains (10%-12% moisture).