Levulinic acid as a catalyst for the production of 5-hydroxymethylfurfural and furfural from lignocellulose biomass

Levulinic acid (LA) was used as a catalyst for the first time to produce 5-hydroxymethylfurfural (5-HMF) and furfural (FAL) from pinewood and eucalyptus sawdust in a mono- or biphasic solvent system. 2-Methyltetrahydrofuran was used as a co-solvent with water in different ratios and temperatures (140–200 8C). Highest yields of 5-HMF and FAL were obtained at 180 8C and 2 h reaction time; however, at 160 8C, high yields of C6 and C5 sugars were obtained. Both hydrolysis and dehydration steps were accelerated in the MTHF/water biphasic system compared to pure aqueous phase. In particular, 1:2 w/ w ratio of MTHF/water resulted in the highest yield of 5-HMF and FAL, whereas 2:1 w/w ratio showed highest yield of C6 and C5 sugars. Increasing the ratio of MTHF/water resulted in a higher fraction of dehydrated products extracted into the organic phase. LA as a catalyst is beneficial because it is miscible in both the phases and the presence of LA favours the equilibrium towards 5-HMF production.