Bio-oil upgrading with catalytic pyrolysis of biomass using Copper/zeolite-Nickel/zeolite and Copper-Nickel/zeolite catalysts

Abstract The bio-oil obtained from a general pyrolysis process contains a higher concentration of oxygenated compounds and the resultant physical and chemical properties make it an unsuitable drop-in fuel. The oxygenated compounds in the bio-oil can be converted into hydrocarbons or less oxygenated compounds with the application of catalysts. This study demonstrated the bio-oil upgrading with the application of catalysts, comparing the catalytic effect of combined mono-metallic catalysts (Cu/zeolite and Ni/zeolite) and sole bi-metallic catalyst (CuNi/zeolite) on the composition of bio-oil and pyrolytic gases. The results demonstrated that in comparison to the combined mono-metallic catalysts, the sole bi-metallic catalyst showed better deoxygenation for all the oxygenated compounds and favoured the production of aliphatic hydrocarbons, whereas the combination of mono-metallic catalysts generated higher proportion of aromatic hydrocarbons in the bio-oil. In both cases, the catalysts equally favoured decarboxylation and decarbonylation reactions, as CO 2 /CO of approximately 1 was obtained during the pyrolysis process.