Bioresource Technology, Vol.251, 143-150, 2018
Improved levulinic acid production from agri-residue biomass in biphasic solvent system through synergistic catalytic effect of acid and products
In this study, levulinic acid (LA) was produced from rice straw biomass in co-solvent biphasic reactor system consisting of hydrochloric acid and dichloromethane organic solvent. The modified protocol achieved a 15% wt LA yield through the synergistic effect of acid and acidic products (auto-catalysis) and the designed system allowed facile recovery of LA to the organic phase. Further purification of the resulting extractant was achieved through traditional column chromatography, which yielded a high purity LA product while recovering similar to 85% wt. Upon charcoal treatment of the resultant fraction generated an industrial grade target molecule of similar to 99% purity with similar to 95% wt recovery. The system allows the solvent to be easily recovered, in excess of 90%, which was shown to be able to be recycled up to 5 runs without significant loss of final product concentrations. Overall, this system points to a method to significantly reduce manufacturing cost during large-scale LA preparation.