Comparison of Staged and Biphasic Organosolv Pretreatment to Facilitate the Production of Lignin-Based Sustainable Aviation Fuel (SAF) from Pelletized Urban Wood Product Wastes

High-yield fractionation and depolymerization to convert woody waste-derived lignin into cycloalkane hydrocarbons is an essential subject to complete the function of sustainable aviation fuel (SAF). However, the biorefinery process needs to be carefully designed to produce small molecular weight monolignol at significant quantity. Our recent studies demonstrate that in comparison to one-pot catalytic transfer hydrogenolysis (CTH), in which large quantity of cellulosic fibres are forming into low value chars, lignocellulosic biomass could produce a higher quantity of SAF after mild fractionation. To upgrade the organosolv induced C-O-C protection during acid catalyzed biomass pretreatment process for treating municipal woody waste, this study performed 24 sets of pretreatment experiments followed by CTH to produce cycloalkane hydrocarbons SAF. We compared the types and yield of SAF precursors after the conventional, staged pretreatment, and biphasic pretreatment over the one-pot CTH approach with detailed lignin-lignin characterization and regression analysis. The results confirmed that all organosolv pretreatment strategies could benefit lignin-lignin dissociation and increase its solubility before CTH. Preservation of β-O-4 linkages up to 42% can benefit the monomer yield by 30% in the downstream process.