Formation kinetics of polycyclic aromatic hydrocarbons (PAHs) during drying process of olive pomace

Abstract

The objective of this study was to evaluate the formation kinetics of polycyclic aromatic hydrocarbons (PAHs) during drying of olive pomace. It was dried at 170, 200 and 230 °C until the final moisture of 5%. PAH analyses were realized after certain drying times and moisture contents. Kinetics of the total PAH formation was comprised with the formation of PAH compounds through the drying process. The highest formation (2224 µg/kg) was observed at 200 °C and 5% moisture after 40 min. This also indicated the significance of drying time and evolution of temperature on the formation of PAH compounds. First order kinetic was applied to determine the kinetic constants as a function of temperature. Total PAH fomration rate constants (k) increased with the drying temperature. Activation energy (E_a) and frequency factor (k₀) values were determined to be 45.9 × 10³ kJ/kg-mol and 18125.95 min^-1, respectively using the Arrhenius equation.

Keywords: Drying; Formation; Kinetics; Polycyclic aromatic hydrocarbons (PAHs).