OrganoCat fractionation of vine shoots for coproduction of bioethanol, furfural, and lignin

Treatment of vine shoots with the OrganoCat method, using a mixture of oxalic acid (0.1 M) in water and 2-methyltetrahydrofuran (1:1) at 140 °C for three hours, allowed a separation of the lignocellulosic biomass into three fractions: an undissolved pulp, an aqueous solution and a solid obtained by evaporation of the organic phase. The resulting pulp was enriched in cellulose with greater crystallinity than the initial one due to the dissolution of the amorphous part, which facilitated enzymatic digestion and produced a significantly high glucose content, close to 70 g/L, and an excellent substrate for ethanol production, reaching levels of 35 g/L. Lignin, was recovered from the organic phase, and hemicellulose-derived sugars in the aqueous phase were converted into furfural (64 % yield from xylose) and ethanol (98 % yield from glucose). Overall, we demonstrate that the OrganoCat method allows an interesting fractionation of the shoots and also enables the full utilization of the obtained fractions that can be efficiently transformed into high-value renewable products such as bioethanol, furfural and high-purity lignin, highlighting the potential of the method as a promising pretreatment technique for the valorization of lignocellulosic biomass. • OrganoCat is an effective fractionation method for the valorization of vine shoots. • All fractions can be transformed efficiently to biofuels and bioproducts. • Hemicellulosic fraction is converted to bioethanol (98 %) and furfural (64 %). • Pulp fraction is efficiently converted to bioethanol (33 g/L, 70 % yield).