Direct production of jet fuel-range bicyclic alkanes from native lignin via a two-step pre-arylation and hydrodeoxygenation strategy

Abstract

The conversion of lignin into high-density jet fuel components represents a promising pathway for sustainable aviation fuel production but is challenged by the inherited low carbon chain of lignin basic structure and self-condensation induced inertness. In this study, we propose a novel two-step strategy involving pre-arylation followed by catalytic hydrodeoxygenation (HDO) to efficiently transform native lignin into bicyclic alkanes suitable as jet fuel components. This approach significantly suppresses condensation reactions during lignin processing and directs product distribution toward C₁₂–C₁₅ bicyclic alkanes, which are key constituents of high-density jet fuel. Using beech wood lignin, the Pd/C-catalyzed HDO process achieved a high yield of bicyclic alkanes up to 39.9 wt%, substantially outperforming conventional non-arylated, formaldehyde-stabilized, and native lignin feedstocks. The method demonstrated broad applicability across diverse lignin sources, including hardwoods, softwoods, and grasses, with yields exceeding 20 wt% in most cases. This work provides a scalable and efficient route for direct lignin valorization into jet fuel-range hydrocarbons, highlighting its potential to support decarbonization efforts in aviation while utilizing renewable biomass resources.