Separation of fiber from distillers dried grains (DDG) using sieving and elutriation

In the dry-grind corn-to-ethanol process, distillers wet grains (DWG) and syrup are blended and dried to produce distillers dried grains with solubles (DDGS). Some dry-grind plants produce distillers dried grains (DDG) as a coproduct instead of DDGS. In these plants, syrup is not mixed with DWG and is sold as a liquid food ingredient or used for energy generation by combustion. We showed recently that, the elusieve process, the combination of sieving and elutriation (upward air flow), was effective in separating fiber from DDGS. The elusieve process could be beneficial in separating fiber from DDG also. In this study, fiber separation from DDG using the elusieve process was evaluated. Elutriation of sieve categories increased neutral detergent fiber (NDF) in the lighter fractions and NDF separation factors were more than 1.0. When DDG is separated via the elusieve process, 11.9% would be obtained as elusieve fiber and 88.1% would be obtained as enhanced DDG. Original DDG had NDF of 36.7% (db), while enhanced DDG would have NDF of 35.3% (db) and elusieve fiber would have NDF of 57.3% (db). Thus, elusieve process produces value-added products from both DDG and DDGS. A detailed economic analysis is needed to ascertain the merits of implementing the elusieve process in a dry-grind plant producing DDG instead of DDGS.