New supercomputing simulations at Oak Ridge National Laboratory are tackling a major bottleneck to cost-effective biofuel production.

Lignin, a major component of plant cell walls, forms problematic clumps during the high-temperature pretreatment of biomass. Until now, it has been unclear how and when the lignin structure changed.

ORNL scientists used the Jaguar supercomputer to determine that lignin collapses to form clumps even at high temperatures, rather than only during the cool-down phase as previously believed.

"This study provides fundamental knowledge that is required to understand the pretreatment process and rationally improve biofuel production," said ORNL co-author Loukas Petridis.

The research is published in the Journal of the American Chemical Society.