Efficient biomass fractionation for levulinic acid production from rice husk

A novel organosolv pretreatment method using solid acid CH₃-SBA-15-SO₃H as a catalyst was developed to overcome the challenges posed by lignin and hemicellulose in rice husk to cellulose conversion, thereby improving the yield of levulinic acid. Through systematic optimization of pretreatment conditions, complete removal of lignin and substantial reduction of hemicellulose from rice husk were achieved within only 40 min at 150 °C, with a minimal cellulose loss of merely 4.8 %. In the γ-valerolactone/water co-solvent system, the presence of both hemicellulose and lignin was found to reduce the yield of levulinic acid. By adopting a two-step process with rice husk as the feedstock, the yield of levulinic acid was significantly increased by 1.77 times. These findings deepen our understanding of biomass conversion and highlight the promising application prospects of solid acid catalysis in sustainable chemical synthesis.