Furfural formation from xylose in heterogeneous catalyzed reactions

The concept of wood biorefinery is envisioned as selective separation of the three main wood components and the subsequent utilization of each fraction for the production of fuels, high value-added chemicals and related products. The pulping industry has developed over the years a number of methodologies for the efficient separation of cellulose from hemicelluloses and lignin which are obtained in form of side streams in the process. Recent years have witnessed much activity to upgrade the sugars to ethanol and other biofuels. An alternative route, namely the dehydration of sugars to furans, is considered as one of the most promising routes for the production of platform chemicals and fuels. Quite recently, furan molecules such as 5-hydroxymethyl-furfural (HMF), furfural (F) and 2,5-furandicarboxylic acid (FDCA) are mentioned in the “Top 10 + 4” in the DOE list as the most rewarding platform molecules (Bozell, J. et al. Green Chem. 2010, 12, 539) The purpose of the current study is to improve the current furfural production (around 50 %mol using mineral acids at aprox. 200 °C) from lignocellulosic biomass applying green chemistry principles. The strategy suggested here is to isomerize xylose to xylulose by a novel solid catalyst with Lewis and Brønsted acid centers and to simultaneously extract the formed xylulose with a ketose carrier. This approach estimates conversion of pentosan into furfural with high yileds (≥80 mol%), low energy consumption and the use of recyclable solid acid catalysts. The results of this analysis could be used to produce platform chemicals from lignocellulosic biomass, that could be further synthesized for applications in a wide range of industrial branches (biofuel, pharmaceutical, agroindustry, chemical, among others). The findings may be useful in the production of lignocellulosic-based value-added chemicals.