The conversion of wood into chemicals for the production of most of our synthetic plastics, fibers, and rubbers is technically feasible. Synthetic oils from liquefaction of wood might serve as feedstocks for cracking into chemicals in the same way that crude oil is presently used.

Upgrading of condensed liquid from biomass involves three stages. There are physical upgrading (differential condensation, liquid filtration, and solvent addi­tion), catalytic upgrading (deoxygenating and reforming), and chemical upgrading (new fuel and chemical synthesis).

The bio-oil obtained from the fast pyrolysis of biomass has high oxygen content. Because of the reactivity of oxygenated groups, the main problem of the bio-oil is its instability. Therefore, study of the deoxygenation of bio-oil is needed. In previous

work the mechanism of hydrodeoxygenation (HDO) of bio-oil in the presence of a cobalt molybdate catalyst was studied (Zhang et al. 2003).

The main HDO reaction is represented in Equation 8.1:

-(CH2O)- C H2 ! -(CH2)- C H2O (8.1)

This is the most important route of chemical upgrading. Reaction 8.1 has strong analogies with typical refinery hydrogenations like hydrodesulfurization and hy­drodenitrification. In general, most of the HDO studies have been performed using existing hydrodesulfurization catalysts (NiMo and CoMo on suitable carriers). Such catalysts need activation using a suitable sulfur source, and this is a major drawback when using nearly sulfur-free resources like bio-oil.