Catalytic assessment of ion exchange-based bifunctional catalysts for the hydrogenation of levulinic acid to y-valerolactone.

Abstract

Nowadays, most of the energy and chemicals come from fossil fuels. Nevertheless, there is a growing concern about the depletion of fossil resources and the respective environmental problems they cause in terms of the greenhouse effect. Lignocellulose-derived platform molecules are being investigated as a possible solution. Among the platform molecules derived from biomass we can distinguish levulinic acid, which through a hydrogenation reaction can produce -valerolactone, which has multiple applications. On this research, the hydrogenation reaction of levulinic acid to produce -valerolactone has been catalysed with bifunctional ion exchange resins. An initial assessment of the operating conditions has been carried out with Amberlyst CH28 catalyst. As a result of the evaluation, it was found that it is better to work with a water-diluted LA feed, at a temperature of 120 °C and that the catalyst loading, when the hydrogen pressure is limited to 7 bar, does not favour the catalytic activity. The LA hydrogenation reaction has also been performed to produce GVL with 4 bifunctional copper and palladium resins, which have been doped in the faculty's laboratory. From this study it has been observed that copper doped resins show a higher conversion. Palladium resins, on the other hand, are more selective. In addition, it has been noted that resins with macroreticular structure show higher LA conversion than gel-type resins. Despite this fact, gel-type resins show better selectivity to produce GVL. Lastly, it should be noted that both the levulinic conversion and the GVL selectivity of the reaction under the conditions tested were very low and need to be further studied.