High concentration levulinic acid production from corn stover

Abstract

In this study, a novel approach is presented for high concentration levulinic acid (LA) production from biomass hydrolysate. In this process, saccharified biomass hydrolysate, prepared from acid pretreatment of corn stover, was used as the feed. Previously introduced simultaneous isomerization and reactive extraction (SIRE) and back-extraction (BE) method was implemented to convert glucose from biomass hydrolysate solution to fructose at high yield, 88%, and then fructose was transferred to an acidic aqueous reaction medium. In the acidic aqueous medium, not only fructose was converted at high yield (63 mol%) and facile reaction conditions (95 °C and autonomous pressure) to LA, but also the resulting LA was provided at a significant loading of 6.4 wt%. The required energy for LA isolation (95% purity) by evaporation was calculated by Aspen plus simulator software. Results indicated that for high LA concentration (6.4 wt%), required energy (57 400 kJ kg⁻¹ LA) is 18 times less than in the case where LA loading was 1 wt% (1 043 000 kJ kg⁻¹ LA). This dramatic reduction in the energy consumption makes the process more cost competitive. The proposed process also benefits from low energy inputs, recyclable streams and catalysts.