Bio-oil composition can differ depending on the biomass feedstock. Such information is essential if upgrading to a liquid fuel or to platform chemicals is intended. Furthermore, water and inorganic elements have to be taken into account for the catalyst selection. In this work, two bio-oils from wheat straw and beech wood were characterized by different techniques. Both were composed by a light and a heavy phase separately analyzed. The water content of the fractions differed over a wide range between 14.4 and 56.7 wt.% and therefore also the HHV (between 28.5 and 9.2 MJ/Kg). Both phases showed very low content of sulfur (<0.4 wt.%), which can have influence the lifetime of the catalyst. The 1H-NMR integration showed higher values in the regions of alkanes, carboxylic acid or keto-groups, and hetero-(aromatics) for both heavy phases, while light phases showed higher values in the water, O-H exchanging and carbohydrates region. So the heavy phases seem to be a good basis if phenols and its derivatives are expected and the light phases if alcohols are of interest. These results show that the bio-oils composition is essential for upgrading reactions, impacting on the products as well as on the choice of the catalyst.

Proceedings of the 25th European Biomass Conference and Exhibition, 12-15 June 2017, Stockholm, Sweden, pp. 1143-1147