(364a) One Pot Production of Levulinic Acid from Lignocellulosic Biomass Using a Catalytic Membrane Reactor

Conversion of cellulosic biomass to levulinic acid (LA), a platform chemical for bioplastics and hydrocarbon fuels has become a major focus for biomass conversion. Currently, most of the levulinic acid production processes from lignocellulosic biomass rely on the corrosive homogeneous acid or toxic metal-based catalyst. Here a polymeric solid acid catalyst is designed and synthesized to directly convert cellulosic biomass to levulinic acid in one step at mild conditions without pretreatment with high selectivity and high conversion. Moreover, the catalyst is immobilized on a membrane substrate which enables the immediate separation of the levulinic acid product from the reactor driving the reaction to completion and improving the yield. Here the production of levulinic acid is optimized by varying the reaction conditions including the solvent, solvent mixture, reaction time and temperature for a variety of biomass feedstock. In particular, green solvent mixtures comprising ionic liquid or water with γ-valerolactone (GVL) are found to improve the selectivity and yield for the levulinic acid production. Levulinic acid yields up to 90% have been achieved at mild reaction conditions from different lignocellulosic biomass including nut shells and husks, corn stover, rice husks, and wheat straws. In addition, our solid acid catalyst is reusable, less corrosive, environmentally friendly and is a promising technology for realizing future biorefinery.