Levulinic acid production from furfural: process development and techno-economics

Several efforts have been made to develop catalysts and processes to effectively produce levulinic acid (LA) from biomass. However, the conversion of hemicellulose/furfural (FF) to LA via hydrogenation is an energy-intensive and low effectiveness step. Here, we report a novel, rapid, and green route for LA production from bio-derived furfural in a microwave (MW) reactor via hydroxymethylation followed by rehydration. The influence of various reaction parameters on the product distribution was studied. The yields of 5-hydroxymethylfurfural (HMF) and LA were higher at lower (160 °C) temperature ranges, respectively. The rate of HMF rehydration to LA was higher over pure Amberlyst-15. A LA selectivity of 60% at 74% FF conversion was obtained at a 2 : 1 formalin : furfural ratio, 160 °C, and 5 min in the MW reactor. The FF conversion and LA yield were enhanced by 3.5 and 4.6 times with MW heating as compared to those via conventional heating. The LA yield decreased by 2.7 times with the increase of furfural concentration from 10 to 50 wt%, at constant catalyst loading. The process flow and percentage carbon Sankey flow diagrams were developed. The techno-economic analysis suggested that LA can be produced at a minimum selling price (MSP) of $1349 per metric ton, considering the FF market price as $1000 per metric ton and a discount rate of 10%. Based on the present study and our previous works, the MSP of LA from lignocellulosic biomass (LB) was $1011 per metric ton. The process developed in this study in combination with those in our previous works can be utilized to economically convert both cellulosic and hemicellulosic parts of the LB to LA.