Breakdown of cell wall nanostructure in dilute acid pretreated biomass.
The generation of bioethanol from lignocellulosic biomass holds great promise for renewable and clean energy production. A better understanding of the complex mechanisms of lignocellulose breakdown during various pretreatment methods is needed to realize this potential in a cost and energy efficient way. Here we use small-angle neutron scattering (SANS) to characterize morphological changes in switchgrass lignocellulose across molecular to submicrometer length scales resulting from the industrially relevant dilute acid pretreatment method. Our results demonstrate that dilute acid pretreatment increases the cross-sectional radius of the crystalline cellulose fibril. This change is accompanied by removal of hemicellulose and the formation of R(g) ∼ 135 A lignin aggregates. The structural signature of smooth cell wall surfaces is observed at length scales larger than 1000 A, and it remains remarkably invariable during pretreatment. This study elucidates the interplay of the different biomolecular components in the breakdown process of switchgrass by dilute acid pretreatment. The results are important for the development of efficient strategies of biomass to biofuel conversion.
Pingali
Sai Venkatesh
SV
Center for Structural Molecular Biology and Molecular Bioscience and Biotechnology Group, Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA. pingalis@ornl.gov
Urban
Volker S
VS
Heller
William T
WT
McGaughey
Joseph
J
O'Neill
Hugh
H
Foston
Marcus
M
Myles
Dean A
DA
Ragauskas
Arthur
A
Evans
Barbara R
BR
D000143:Acids / Q000378:metabolism*; D018533:Biomass; D002473:Cell Wall / Q000737:chemistry* / Q000378:metabolism*; D000431:Ethanol / Q000737:chemistry; D008031:Lignin / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D049329:Nanostructures / Q000737:chemistry*; D033363:Neutron Diffraction; D008897:Panicum / Q000737:chemistry*; D053838:Scattering, Small Angle
D000143:Acids; C036909:lignocellulose; D000431:Ethanol; D008031:Lignin