Glycerol-Derived Solvent Platforms for Lignin-First Biorefining toward Functional Aromatic Streams

Dr. James Sheehan is an Assistant Professor in the Department of Chemical & Biological Engineering at the University of Alabama. He received his PhD in Chemical Engineering from the Pennsylvania State University in 2019 under the advisement of Dr. Phillip E. Savage. His research group focuses on advancing lignocellulosic biorefining and supercritical fluid modification of polymer composites. Dr. Sheehan serves on the Early Career Board of ACS Sustainable Chemistry & Engineering and is the Secretary and Programming Committee Chair for the AIChE Forest & Plant Bioproducts Division. He is a recipient of the ACS Petroleum Research Fund Doctoral New Investigator Award, and his research program has been supported by the National Science Foundation (NSF) and the USDA National Institute of Food and Agriculture (USDA NIFA). His work aims to integrate fundamental chemical engineering with green chemistry principles to enable scalable, sustainable technologies for biomass conversion and modification.

Lignin, which constitutes 20–30 wt% of forestry and agricultural residues, represents the largest renewable source of aromatic carbon on the planet. Unlike conventional petrochemical aromatic streams dominated by benzene, toluene, and xylenes, lignin-derived aromatics intrinsically contain oxygenated functional groups that open pathways to higher-value applications in fine chemicals, flavorants, pharmaceuticals, and advanced materials. Harnessing this potential requires solvent systems that can both access and selectively deconstruct lignin’s complex polymeric architecture under practical processing conditions. This presentation highlights recent advances in glycerol-derived ethers (GDEs) as versatile solvent platforms for lignin-first biorefining. These solvents—prepared by etherifying the glycerol scaffold—offer a unique combination of high boiling points, dramatically reduced viscosities, and tunable polarity, enabling efficient lignin solvation and extraction under mild thermochemical conditions. Case studies will demonstrate how GDEs facilitate both organosolv delignification and, when used as hydrogen-donor media, enable transfer-hydrogenolysis pathways that convert lignin into streams of functionalized aromatic monomers without the need for high-pressure hydrogen. Together, these examples illustrate how rational solvent engineering can address long-standing challenges in lignin valorization. The talk will conclude by benchmarking glycerol-derived solvent systems within the broader landscape of lignin-first biorefining technologies using green chemistry metrics. This quantitative perspective will highlight key technical bottlenecks, opportunities for innovation, and future research directions critical for advancing lignin-derived aromatics as a foundation of sustainable chemical manufacturing.