Suffolk Reporter

Georgia Tech researchers have introduced a more efficient method for converting lignin, an organic polymer found in wood and plants, into valuable chemicals. Collaborating with Eli Stavitski from the National Synchrotron Light Source II (NSLS-II), part of the U.S. Department of Energy’s Brookhaven National Laboratory, the team used X-ray absorption spectroscopy to analyze their innovative process.

Lignin constitutes about 20 to 30 percent of the dry mass of wood and other plants but has traditionally been challenging to break down due to its complex structure. This often results in lignin being discarded as waste during paper production and other plant-based processes.

The research team at Georgia Institute of Technology employed mechanocatalysis, which utilizes physical forces like vibration or rotation in a ball mill, to drive chemical reactions without solvents, heat, or high pressure. Carsten Sievers from Georgia Tech's School of Chemical and Biomolecular Engineering highlighted that traditional depolymerization methods involve solvents and complicated separation steps. In contrast, their approach uses steel balls in a ball mill to facilitate solid-state reactions.

Graduate student Erin Phillips worked with palladium catalysts for breaking down lignin's bonds. Palladium is known for its ability to store hydrogen, enhancing reaction efficiency. The team's findings showed that their palladium catalysts could break lignin model compounds' bonds up to 300 times faster than nickel-based catalysts under similar conditions.

“This remarkable increase in efficiency means that the process can produce more phenol and other valuable chemicals in a shorter amount of time,” Phillips stated.

Previously, Sievers’ group demonstrated that hydrogenolysis using nickel catalysts could convert lignin compounds with hydrogen. However, this new method offers improved reaction speed and efficiency.