10-27: Interactions of ferrous and ferric ions with oxygen and biomass:  Impacts on the efficiency of dilute acid pretreatment of biomass

Tuesday, April 30, 2013
Exhibit Hall
Hui Wei1, Xiaowen Chen2, Wei Wang1, Bryon S. Donohoe1, Peter N. Ciesielski1, Shi-You Ding1, Michael E. Himmel1 and Melvin P. Tucker2, (1)Biosciences Center, National Renewable Energy Laboratory, Golden, CO, (2)National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO
Recently developed iron co-catalyst enhancement of dilute-acid pretreatment of biomass is a promising technology for enhancing sugar release from recalcitrant lignocellulosic biomass. Progress has been made in understanding the mechanisms of this enhancement; however, the efficacy of this enhancement has been variable. Therefore, the consistent application of this technology requires addressing this variation.  The objective of this study was to assess the impact of multiple factors on the efficiency of biomass pretreatment, including the chemical nature of the inner wall of the reactor, the redox state and concentration range of metal ions, and the interactions between metal ions and biomass.  We have observed that by controlling oxygen in the microenvironment of the reactor and preventing the release of metal ions responsible for sugar degradation from the inner wall of reactor, both ferrous and ferric ions are efficient at enhancing sugar release during dilute acid pretreatment of biomass.  These results are crucial not only for our understanding of the mechanism of metal ion-enhancement of biomass pretreatment, but also to enable scale-up of this technology.