Production of liquid transportation fuels from cellulose via intermediate formation of gamma-valerolactone

The effective conversion of biomass to biofuels through intermediate chemical building blocks is attracting considerable attention. Among these building blocks, gamma-valerolactone (GVL), which can be formed from levulinic acid, offers a flexible platform for the production of fuels and chemicals. However, few works have addressed the direct production of GVL from biomass, which conventionally requires an energy intensive separation of levulinic acid from the mineral acid (e.g., sulfuric acid) used as catalyst in the cellulose deconstruction process. Herein, we present different strategies to produce sulfuric acid-free GVL from cellulose, with reduced energy demand, via the production of levulinic acid and/or levulinate esters that separate spontaneously from aqueous solution of sulfuric acid. This GVL can be converted into liquid fuels by different catalytic pathways such as by ring-opening and decarboxylation to CO₂ and butene, combined with oligomerization to C₈₊ olefins, or by production of 5-nonanone, which can be converted to nonene or C₁₈ olefins for use in diesel fuel.