Distiller?s grains are a byproduct of corn ethanol production and provide an opportunity for increasing the economic viability and sustainability of the overall grain-to-fuels process. Typically, these grains are dried and sold as a ruminant feed adjunct. Here, this study considers utilization of the residuals in a novel supplementary fermentation process to produce two products, enriched protein and fusel alcohols. The value-added proposition and environmental impact of this second fermentation step for distiller?s grains are evaluated by considering three different processing scenarios. Techno-economic results show the minimum protein selling price, assuming fusel alcohol products are valued at 0.79 cents per liter gasoline equivalent, ranges between 1.65?2.48 kg protein<
sup>
?1<
/sup>
for the different cases. Environmental impacts of the systems were evaluated through life cycle assessment. Results show a baseline emission results of 17 g CO<
sub>
2-eq<
/sub>
(MJ fuel)<
sup>
?1<
/sup>
for the fuel product and 10.3 kg CO<
sub>
2-eq<
/sub>
kg protein<
sup>
?1<
/sup>
for the protein product. Sensitivity to allocation methods show a dramatic impact with results ranging between ?8 to 140 g CO<
sub>
2-eq<
/sub>
(MJ fuel)<
sup>
?1<
/sup>
for the fuel product and ?0.3 to 6.4 kg CO<
sub>
2-eq<
/sub>
kg protein<
sup>
?1<
/sup>
for the protein product. The discussion is focused on the potential impact of the technology on corn ethanol production economics and sustainability.