The objective of this study is to catalytically upgrade fast pyrolysis vapors of sawdust using various Fe-based catalysts for producing phenolic-rich bio-oil by analytical pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) technique. A variety of parameters, including support
characteristic, calcination temperature, pyrolysis temperature, as well as the catalyst-to-biomass ratio during the pyrolysis process were evaluated for their effects on product distribution of bio-oil. GC-MS analysis showed that compared to Fe–Mg and Fe–Al catalysts, the developed
Fe–Ca catalyst significantly promoted the formation of phenols and its derivatives. The phenolic concentration declined with increasing calcination temperature and pyrolysis temperature, while increased monotonically along with increasing catalyst-to-biomass ratio. The phenolics concentration
was high upto 81% (peak area) under optimum conditions of calcination temperature of 500 °C, pyrolysis temperature of 600 °C and catalyst-to-biomass ratio of 10. At higher catalyst-to-biomass ratio of 20, phenolics (88.03% in peak area) and hydrocarbons (including 7.86% of aromatics
and 4.1% aliphatics) were the only two components that can be detected, with all the acids, aldehydes and ketones completely eliminated. This indicated the excellent capability of developed Fe–Ca catalyst in promoting the decomposition of lignin in biomass to generate phenolic compounds
and meanwhile inhibiting the devolatilization of holocellulose.
Kinetic Modeling of the Ignition of Droplets of Fast Pyrolysis Bio-oil: Effect of Initial Diameter and Fuel Composition