Catalytic fast pyrolysis of olive stone for bio-oil deoxygenation.

Abstract

In this work, conventional, fast and catalytic fast pyrolysis of olive stone residues were studied with a commercial catalyst with mild acidity, γ-Al2O3, an activated carbon from olive stones (AC) prepared by chemical activation with phosphoric acid and the same activated carbon loaded with Zr as active phase (ACZr). The results showed that fast pyrolysis has a higher content of liquid fraction (64 %wt) than that obtained in conventional pyrolysis (52 %wt), due to cracking reactions occur at a lesser extent. In the catalytic fast pyrolysis, the acid character of the catalysts favors the cracking and deoxygenation reactions that reduce the production of the liquid fraction, mainly producing an increase in the phenols species and a decrease in the acid species. On the other hand,a clear increment in the content of CO can be observed (conventional and catalytic fast pyrolysis, respectively), due to decarbonylation reactions, which are favored in the presence of catalysts.