Modelling of succinic acid heterogeneous catalytic ozonation on metallic foam

• A metallic foam was used in a catalytic ozonation device.
• The concentration of the model molecule decreased linearly with ozonation time.
• Modelization of the concentration pattern was consistent with the experimental results.
• Above a given concentration of compound, the rate reached a constant value.
• Results suggest catalytic ozonation proceeds through two successive reaction steps.

This work aims at envisaging the use of a solid catalyst in the catalytic ozonation process to avoid the separation step needed after the treatment for catalyst recovery when powdered material is involved. This work devoted to the removal of succinic acid (SA), a low molecular weight refractory organic acid whose heterogeneous catalytic ozonation was previously studied using powder form catalysts. Heterogeneous catalytic ozonation of succinic acid was carried out in a reactor fitted with a recirculation loop. This study investigated if the location of the solid catalyst, i.e. inside the reactor in the zone of ozone transfer or in a cartridge placed on the recirculation loop, had an influence on the amount of SA removed or on the elimination rate expression. No influence of the catalyst location was detected. The rates of SA removal by catalytic ozonation were found to depend on both the catalyst concentration and the initial SA concentration for weak SA initial concentrations, but only on the catalyst concentration for greater initial SA concentrations. The pattern of SA concentration from modelization closely matched the experimental results. This implementation of the catalytic ozonation process with solid catalyst is of interest for the application at industrial scale. The 1.8 ratio between the rates of SA and DOC removal showed that mineralization to CO2 did not occur simultaneously with SA removal.