Cascade strategy for the catalytic valorization of biomass derived-levulinic acid and ɤ- valerolactone to 2-methyl-tetrahydrofuran and 2-butanol

Nowadays the development of clean energy sources for the future is a principal benchmark and in this respect biomasses are very promising renewable starting materials. In fact, they can be converted into interesting platform chemicals, such as 2-furaldehyde, 5-hydroxymethyl-2-furaldehyde, levulinic acid and gamma-valerolactone. Therefore, the possibility of upgrading these already valuable chemical intermedies in other compounds of surplus value such as 2-methyl-tetrahydrofuran and 2-butanol represents a challenging route. At the moment the industrial production of 2-butanol starts from the C4-hydrocarbon mixture derived from steam cracking of heavy oil fractions. Here, an alternative process combining hydrogenation-decarboxylation of levulinic acid and of gamma valerolactone to selectively give 2-butanol or methyl-THF was studied in the presence of Ru, Pd and Re catalytic systems. The effect of reaction conditions was investigated and in particular the optimization of the composition of the catalytic system allows us to obtain different target products, such as MeTHF and 2-BuOH. This preliminary study was carried out in water as solvent employing only heterogeneous commercial catalytic systems, more economic and easily available respect to ad hoc prepared ones. Moreover, the addition of acid co-catalysts and/or of Re/C significantly modifies the reactivity of the studied substrates. This approach evidences the wide range of possible molecules obtainable from bioresources with potential applications for fine chemicals and biofuel productions.