Polymeric Solid Acid Catalysts for Efficient Hydromethyfurfural and Levulinic Acid Production from Biomass Feedstock

Polymeric solid acid catalysts were synthesized and optimized for the production of reducing sugars, HMF and levulinic acid from biomass feed stock. The catalysts consist of a poly(sulfonic) acid chain and a poly(ionic liquid) chain grafted on a solid substrate. Crystalline cellulose as well as dilute acid, base and steam pretreated biomass samples from National Renewable Energy Laboratory were investigated with our novel tunable catalysts in ionic liquid solvent and ionic liquid/water, ionic liquid/GVL solvent mixtures. Over 95% of total reducing sugar (TRS), over 70% HMF and over 50% levulinic acid yields were obtained from pure cellulose samples at 105^oC, 135^oC and 155^oC respectively. For the pretreated biomass samples, different yields were obtainded from three different pretreatment methods. Yields of over 80% TRS, over 60% HMF/Furfural, and over 40% levulinic acid were achieved. GVL cosolvent was found to facilitate the conversion process whereas the opposite is true for water. Our results demonstrate the high catalytic activity and versatility of these unique polymeric acid catalysts.