In this study, a practical process for ozonization of benzyl alcohols to ketones and aldehydes in a rotating packed bed (RPB-O-3) reactor has been developed. Using 1-phenylethanol as a model reactant, the performance of RPB-O-3 process in different solvents has been compared with the commonly used stirred tank reactor (STR-O-3). Ethyl acetate was the optimum solvent for the conversion of 1-phenylenthanol to acetophenone in RPB-O-3 process, with 78% yield after 30 min. In a parallel STR-O-3 experiment, the yield of acetophenone was 50%. Other experimental variables, i.e. O-3 concentration, reaction time, high-gravity factor and liquid flow rate were also optimized. The highest yield of acetophenone was obtained using O-3 concentration of 80 mg.L-1, reaction time of 30 min, high gravity factor of 40 and liquid flow rate of 120 L.h(-1). Under the optimized reaction conditions, a series of structurally diverse primary and secondary alcohols was oxidized with (19%-92%) yield. The ozonization mechanism was studied by Electron Paramagnetic Resonance (EPR) spectroscopy, monitoring the radical species formed upon self-decomposition of O-3. The characteristic quadruple peak with the 1:2:2:1 intensity ratio that corresponds to hydroxyl radicals (center dot OH) was observed in the electron paramagnetic resonance (EPR) spectrum, indicating an indirect oxidation mechanism of alcohols via center dot OH radical. (C) 2020 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd. All rights reserved.