Characterisation of bio-oil and its sub-fractions from catalytic fast pyrolysis of biomass mixture

The present study aim is to characterise catalytic and non-catalytic biomass pyrolysis liquid products. Turkey is the world’s largest hazelnut producer and also ranks fifth in tea production, so a mixture of hazelnut shell, tea bush and hazelnut knot was selected as the biomass sample, and vanadium pentoxide (V₂O₅) was also used as a catalyst. Considering the biomass mixture and catalyst used, this research is unique for the literature. Bio-oils, which are obtained by catalytic and non-catalytic processes and collected in two sub-fractions, were characterised. The sub-fractions of toluene and ethyl acetate, there was a significant increase in calorific values compared with the mixture without catalyst, because of the decrease in the amount of oxygen and increase in the amount of carbon. The increase in this calorific value in the toluene sub-fraction is about 76% higher than the raw material mixture. In the sub-fractions of toluene and ethyl acetate produced by catalytic pyrolysis, an increase in carbon content was observed when compared with non-catalytic products, while the amounts of oxygen decreased. Considering the results, the toluene sub-fraction is generally composed of phenolic structures. Generally, the ethyl acetate sub-fraction comprises the carbonyl group – containing ketone and aldehyde structures as well as aromatic and phenolic compounds. The resulting bio-oil has the potential to be used as a liquid fuel both in terms of calorific values and in terms of the H/C and O/C ratio.