https://doi.org/10.15255/KUI.2001.044
Published: Kem. Ind. 51 (6) (2002) 259–266
Paper reference number: KUI-44/2001
Paper type: Original scientific paper
Mass Transfer Resistances in the CuY-5 Catalysed Oxidation of Phenol
Z. Barjaktarović and S. Zrnčević
Abstract
Phenol is common and important pollutant found in the effluent streams of variety of chemical plants, including coal processing plants and refineries. In the conventional wet air oxidation of phenol, a significant induction period, followed by rapid reaction phase is observed. The induction period represents the time taken to establish a minimum radical concentration for phenol oxidation. At the conditions typical of wet air oxidation processes, hydrogen peroxide is a known source of the highly reactive hydroxyl radical. Therefore, oxidation of phenol with hydrogen peroxide and oxygen on zeolites catalyst CuY-5 was studied in this work. The effects of internal and external mass transfer resistances on reaction rate were investigated. Reaction was performed in stirred slurry reactor at different oxygen loadings (0-130 cm3 min-1), stirrer speeds (200-800 min-1), catalyst loadings (0.05-0.4 g) and concentrations of catalytic active material. The initial phenol concentration was 0.01 mol dm-3 and the initial hydrogen peroxide concentrationwas 0.03 mol dm-3. The experimental results indicate that the gas-liquid and liquid-solid mass transfer resistance showed no effect on the oxidation of phenol, i.e. that the reaction was performed in kinetic regime. These observations were consistent with the values of Dammköhler and Thiele numbers 4,9 X 10* and 3,88 X 10-4, respectively. It has been found that the reaction rate increases with increasing the catalyst loading and concentrations of the active material at a carrier. On the other hand, different oxygen loadings and stirrerspeeds showed no effect on the reaction rate.
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Keywords
phenol oxidation, mass transfer resistance, zeolite CuY-5