Scaling up and benchmarking of ethanol production from pelletized pilot scale AFEX treated corn stover using Zymomonas mobilis 8b

This report outlines the recent scale-up of AFEX pretreatment from the laboratory to pilot scale. Sugar yields were improved by 19 and 15% for glucose and xylose, respectively. Further improvement was achieved when scaling up the hydrolysis and fermentation of AFEX-treated corn stover to 2500 L working volume. Benchmarking was performed using CTec 3 and HTec 3 enzymes along with Zymomonas mobilis 8b. Subsequently, the seed train was modified to use a hydrolysate-based medium as a replacement for pure sugars and nutrients. Fermentation performance was comparable following this change. Economic analysis showed a 19% reduction in MESP for the new process over the previous benchmark process.