(652d) Co-Solvent Enhanced Production of Fuel Precursors From Lignocellulosic Biomass

Lignocellulosic biomass is the most abundant source of organic carbon on Earth and presents the only option with the potential to economically and sustainably replace fossil resources for large-scale production of liquid transportation fuels.  Furfural, 5-hydroxymethylfurfural (5-HMF), and levulinic acid (LA) are promising platform chemicals made by dehydration of biomass sugars and can be catalytically hydrogenated to gasoline, jet fuel, diesel-range alkanes, and fuel blending components compatible with the existing fuel infrastructure (so-called “drop-in” fuels).  However, the natural resistance of lignocellulose to breakdown to fuel precursors including monomeric sugars and their dehydration products is the major obstacle to low cost fuels and must be overcome for biomass fuels to be economically competitive. Here, we demonstrate that tetrahydrofuran (THF) is uniquely suited as a water-miscible co-solvent to promote biomass deconstruction, sugar dehydration, and lignin extraction simultaneously and achieve much higher selectivity to fuel precursors than previously reported. We propose a novel biomass-to-fuels platform in which THF is both a recoverable co-solvent and final co-product and compare the performance of this system using different raw substrates and various acid catalysts to achieve the targeted production of fuel precursors without the need for additional pretreatment. We also discuss the advantages of co-solvent strategies for the direct processing of raw feedstock in comparison to two-phase and steam-stripping operations.