Transformation of Sorbitol to Biofuels by Heterogeneous Catalysis: Chemical and Industrial Considerations

Abstract

Decreasing oil supplies and increasing energy demand provide incentivesto find alternative fuels. First, the valorisation of edible crops forethanol and biodiesel production led to first generation biofuels.Nowadays, research is focused on lignocellulosic biomass as a source ofrenewable carbon (second generation biofuels). Whereas the cellulosicethanol production is in progress, a new way consisting of thetransformation of ex-lignocellulose sugars and polyols towards lighthydrocarbons by heterogeneous catalysis in aqueous phase has beenrecently described.This process is performed under mild conditions (T < 300 degrees C and P< 50 bar). It requires on one hand hydrogen formation by catalyticreforming of carbohydrates in aqueous phase and on the other hand, thedehydration/hydrogenation of polyols leading to alkanes by selective C-Obond cleavages. The challenge here is to conceive multifunctionalcatalytic systems that are stable, active and selective under thereaction conditions.The aim of this article is to present the involved reactions, thecatalytic systems described in literature for that kind oftransformation and examples of industrial applications.