Catalytic wet oxidation of phenol in batch and trickle bed reactors over a Pt/TiO(2) catalyst.

摘要

Batch and trickle bed experiments were performed using 4.45% Pt/TiO 2 catalyst to study catalytic wet oxidation of phenol in the temperate range 150--205°C. It was found that phenol conversion was complete within five minutes to two hours, depending on the temperature and the catalyst loading. Total organic carbon oxidation was near complete, typically between 90 and 95% oxidation. The residual products of oxidation were found to be carboxylic acids, which are readily biodegradable. Pressure effects were mild, although oxygen concentration gradients were found to be significant in the catalyst pellets used in the flow reactor. Long term catalyst deactivation was observed in the trickle bed reactor with a one-third reduction of catalyst activity after 3 weeks of continuous operation.;Reaction rate modeling was performed based on batch results for both phenol oxidation as well as overall TOC oxidation. Extensive three phase trickle bed modeling was performed using a three phase reactor model and the model equations were solved using the orthogonal collocation of finite elements technique. Batch derived kinetic models with externally measured values and theoretically calculated parameters were used to predict trickle bed performance accurately for both phenol and TOC conversions.