Esterification of Levulinic Acid into Ethyl Levulinate Catalyzed by Sulfonated Bagasse-carbonized Solid Acid

A sulfonic carbon-based catalyst (C-SO3H) was successfully prepared by sulfonating incompletely carbonized sugarcane bagasse. The optimized catalyst of high activity in the esterification of levulinic acid (LA) with ethanol was produced under sulfonation at 150 degrees C for 15 h with a 75 mL/g sulfonation ratio. The prepared catalysts were characterized by X-ray powder diffraction (XRD), Fourier transform infrared (FTIR) analysis, scanning electron microscopy (SEM), and elemental analysis (EA). The bagasse-carbonized catalyst was porous, and the porous structure remained unchanged after sulfonation treatment. Moreover, the introduced acidic group was the catalytic center. A high yield of ethyl levulinate (ELA) of 88.2% was obtained at 120 degrees C for 9 h. The sulfonic carbon-based catalyst could be reused at least five times and still exhibited great stability. The application of the sulfonic carbon-based catalyst was not only the effective use of biomass resources but also promoted the production of various high value chemicals.