No abstract

The use of activated carbon cloths as supports for Pd catalyst has been investigated in a hydrodechlorination process. Using p-chlorophenol (CP) as a model compound, the influence of the catalyst preparation procedure and Pd content have been studied at 30−85 °C, showing good activity and selectivity. Kinetic analysis of these diffusion-independent results showed the reaction to be first-order with respect to each reactant concentration (CP and hydrogen). Analysis of diffusion and reaction shows that diffusion resistance will be significant in granules larger than 100 μm. Several simulations of adsorption, diffusion, and reaction are presented showing the effect of pellet size, of hydrogen pressure, and of adsorbent loading.

The use of glass fibers in the form of woven cloth (GFC), as a new type of catalytic support, was studied for the reduction of aqueous nitrate solutions using a Pd/Cu-GFC catalyst. The activity (per gram Pd) and selectivity to nitrogen were found to be comparable with those found for Pd-Cu catalysts supported on the other carriers. The maximal initial removal activity was found for a catalyst with a Pd/(Pd + Cu) ratio of 0.81. The corresponding activity was 0.7 mmol min −1 (g Pd ) −1 , and the selectivity was 97 mol% at 25 • C and pH 6.5 for initial nitrate concentration of 100 mg l −1 . The selectivity to nitrogen declined at high conversions of nitrate and high pH.

No abstract

No abstract