There's an old saying in the biofuels industry: "You can make anything from lignin except money." But now, a new study may pave the way to challenging that adage. The study from the Energy Department's National Renewable Energy Laboratory (NREL) demonstrates a concept that provides opportunities for the successful conversion of lignin into a variety of renewable fuels, chemicals, and materials for a sustainable energy economy.
"Lignin Valorization Through Integrated Biological Funneling and Chemical Catalysis" was recently published in the Proceedings of the National Academy of Sciences. The NREL-led research project explores an innovative method for upgrading lignin.
The process for converting glucose from biomass into fuels such as ethanol has been well established. However, plants also contain a significant amount of lignin up to 30 percent of their cell walls. Lignin is a heterogeneous aromatic polymer that plants use to strengthen cell walls, but it is typically considered a hindrance to cost-effectively obtaining carbohydrates, and residual lignin is often burned for process heat because it is difficult to depolymerize and upgrade into useful fuels or chemicals.
"Biorefineries that convert cellulosic biomass into liquid transportation fuels typically generate more lignin than necessary to power the operation," NREL Senior Engineer and a co-author of the study Gregg Beckham said. "Strategies that incorporate new approaches to transform the leftover lignin to more diverse and valuable products are desperately needed."
Although lignin depolymerization has been studied for nearly a century, the development of cost-effective upgrading processes for lignin valorization has been limited.
In nature, some microorganisms have figured out how to overcome the heterogeneity of lignin. "Rot" fungi and some bacteria are able
|Contact: David Glickson|
DOE/National Renewable Energy Laboratory