Breaking Down the Mechanisms of Biomass Deconstruction

Study reveals insights into plant structural changes during bioenergy pretreatments.

Image courtesy of Thomas Splettstoesser (www.scistyle.com). Reproduced with permission of the Royal Society of Chemistry from Langan, P., et al. “Common processes drive the thermochemical pretreatment of lignocellulosic biomass.” Green Chem. 16, 63–68 (2014).
This graphical representation of lignocellulosic biomass based on supercomputer models illustrates a new study about the inner workings of plant cell walls during bioenergy production.

The Science

Plant cell walls contain substantial amounts of cellulose, hemicellulose, and lignin polymers. Much research is being devoted to developing ways to convert this material (commonly called “lignocellulose”) into fuels. Studying the first step in this process—the breakdown of plant biomass into these three constituents—is particularly difficult because of the complex ways in which the polymers are entangled in the plant cell wall. A new approach has been developed that combines x-ray and neutron beam studies with advanced computational modeling to visualize the deconstruction of biomass in wood chips from aspen trees.

The Impact

This approach has revealed fundamental insights into the mechanisms of biomass breakdown during various pretreatments. This improved understanding will guide the development of more efficient and cost-effective strategies for deconstructing biomass during biofuel production processes.

Summary

The research team, led by scientists at Oak Ridge National Laboratory, studied wood chips as they were exposed to a variety of pretreatments including steam explosion, dilute acid, and ammonia fiber expansion. Researchers visualized structural changes in the biomass during processing, showing, for example, how cell wall porosity and the extent of hydration of the different biomass components change as treatments proceed. The key mechanisms responsible for structural changes are the dehydration of cellulose fibers and lignin-hemicellulose phase separation. The team’s research was featured on the January 2014 cover of Green Chemistry.

Contact

Brian H. Davison
Oak Ridge National Laboratory
davisonbh@ornl.gov

Funding

This research was funded by the Genomic Science program of the Office of Biological and Environmental Research (BER) within the U.S. Department of Energy’s (DOE) Office of Science. The Center for Structural Molecular Biology and the BioSANS beamline is supported by BER using facilities funded by DOE and managed by UT-Battelle, LLC., under contract no. DE-AC05-00OR22725. The research at Oak Ridge National Laboratory’s High Flux Isotope Reactor was sponsored by the Scientific User Facilities Division within DOE’s Office of Basic Energy Sciences. This work also used resources of the National Energy Research Scientific Computing Center, supported by the DOE Office of Science under contract no. DE-AC02-05CH11231.

Publications

Langan, P., et al. “Common processes drive the thermochemical pretreatment of lignocellulosic biomass.” Green Chem. 16, 63–68 (2014). [DOI: 10.1039/C3GC41962B].

Highlight Categories

Program: BES , SUF , BER , BSSD

Performer: DOE Laboratory , SC User Facilities , BES User Facilities , HFIR