ARS | Publication request: Separation of fiber from distillers dried grains (DDG) using sieving and elutriation

Submitted to: Biomass and Bioenergy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 31, 2007
Publication Date: May 1, 2008
Citation: Srinivasan, R., Moreau, R.A., Parsons, C., Lane, J.D., Singh, V. 2008. Separation of fiber from distillers dried grains (DDG) using sieving and elutriation. Biomass and Bioenergy 32:468-472.

Interpretive Summary: During the last five years the fuel ethanol industry in the US has experienced tremendous growth and this growth is expected to continue. For each gallon of fuel ethanol that is produced, about 10 pounds of animal byproduct (coproduct) is produced. This coproduct can be in two forms, distillers dried grains and solubles (DDGS) or distillers dried grains (DDG). DDGS is identical to DDG except that the latter does not contain the distillers solubles, which is a "sticky" syrup. Previously, we developed a new process that reduced the amount of fiber in DDGS, thus making it more palatable to poultry and swine. The current study was designed to evaluate the elusieve process for the first time using Distillers Dried Grains (DDG) instead of DDGS. The results of the study indicated that the process is effective at lowering the amount of fiber in DDG, thus also making the enhanced DDG product more desirable as a feed ingredient for poultry and swine.

Technical Abstract: We recently developed a new process that combined sieving and elutriation (upward air flow) to separate fiber from distillers dried grains and solubles (DDGS). The current study was designed to evaluate the elusieve process for the first time using distillers dried grains (DDG) instead of DDGS. Because DDG does not contain the distillers solubles, which is a "sticky" syrup (which is added to DDGS), it is possible that the elusieve process may be more effective with DDG than with DDGS. In this study, fiber separation from DDG using the elusieve process was evaluated. When DDG is separated via the elusieve process (based on 15% lighter fraction yield from each of the four largest sieve categories), 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). These results indicate the "enhanced DDG" produced by the elusieve process contained 1.4 % less NDF than conventional DDG.