Assignment Task: Biofuels question:
A full-scale 50 MGY (50 million gal/year) dry-grind corn ethanol plant produces 2.8-gal ethanol/bushel of corn (1 bushel=56 Ib). Calculate ethanol production efficiency of this ethanol plant based on the theoretical ethanol yield. Assume that the moisture content of corn is 13% (wb) and the corn starch content is 73% (db). Also calculate the amount of DDGS produced annually, if 17 lb (based on 90% dry wt) of DDGS is co-generated with every 2.8 gal of ethanol produced (Note: ethanol density is 0.789 kg/L; 1 gal=3.785 L) **We need to know the amount of ethanol that can be produced from the starch in a bushel of corn. The theoretical yield of ethanol from corn starch is 0.51 gallons of ethanol per pound of corn starch.