Humans have found uses for woody plants since time immemorial—tools, shelter, firewood. Today, scientists are working to add more major uses to the list: renewable, cost-competitive biofuel and value-added materials.
Turning trees and waste biomass into liquid fuels and other bioproducts has long been a goal of researchers and entrepreneurs, but for many years, the problem proved as unyielding as a stout oak in a storm. This resistance can be traced all the way to the molecules that make up the cell walls of plants, where energy-rich cellulose fibers intermix with hemicellulose and hardy lignin. Much biofuel research has focused on how to design “pretreatment” methods that efficiently separate these components so they can be turned into valuable products.
Using supercomputers, a team from the U.S. Department of Energy’s Oak Ridge National Laboratory has made several fundamental discoveries related to the challenges associated with breaking down biomass. In a recent paper published in Nature Reviews Chemistry, ORNL researchers Jeremy Smith and Loukas Petridis summarize key concepts derived from a decade of molecular-level simulations of biomass systems consisting of thousands to millions of atoms. In addition to determining the molecular structure and characteristics of biomass, the team also uncovered critical forces at work during biomass pretreatment, where heat, water, and solvents are applied in advance of enzymatic deconstruction.
“After 10 years, we’ve formed a coherent viewpoint on how things are working, and we’ve put it down in a succinct way so others can take advantage of the concepts,” said Smith, a University of Tennessee (UT)–ORNL Governor’s Chair and the director of the UT–ORNL Center for Molecular Biophysics. “This review focuses on one particularly important element that has emerged over the years as critical to turning plants into high-value chemicals and biofuels, and that is solvation.”