Molecule-to-molecule conversion of RCF lignin oil to sustainable aviation fuel

This study investigates a fractionation-guided approach to understand the molecular formation of naphthenes for sustainable aviation fuel (SAF) from lignin oil derived via reductive catalytic fractionation (RCF) of pine wood over Ru/C. The lignin oil was separated into six fractions (H100–E100), characterized using advanced analytical methods, and subjected to hydrodeoxygenation (HDO) over phosphidated Ni/SiO2 at 300◦C and 50-bar H2. By correlating feedstock composition with product distribution, the study reveals class-specific transformation pathways and each fraction’s contribution to SAF. Light fractions (H100–H40) showed the highest potential for producing C8–C18 naphthenes, while heavier fractions (H20–E100) yielded fewer SAF-range products due to higher molecular weight. H100 achieved the highest relative carbon yield (74%) and mainly formed mono-naphthenes (C6–C11), especially C9 propyl cyclohexane. By contrast, heavier fractions favored C14–C18 bi-naphthenes, with H60 producing the highest yield of C17 bi-naphthenes (17%).