Optimal temperatures for catalytic regeneration of activated carbon Original Research Article

Activated carbons impregnated with a mixture of copper(ii), iron(iii) and chromium(iii) oxide catalysts were prepared in order to facilitate catalytic regeneration of AC saturated with phenols. The temperature ranges of phenol oxidation (Tp), carbon oxidation (Tc) and carbon burn-off were determined from DTA/TGA investigations in oxidizing and inert atmospheres. The impregnated catalyst facilitated phenol oxidation but also lowered the Tc of the AC. Catalytic regeneration can be conducted between Tp (220–240 °C) and Tc (320–370 °C). Catalytic regeneration of spent impregnated carbon, at 270 °C in flowing air, restored almost all of its initial adsorption capacity and specific surface area while in the absence of a catalyst the regeneration achieved was only 25–30%. The results obtained from the polythermic investigations (DTA/TGA) correlate well with those from the regeneration experiments and, therefore, may be used for determination of temperature conditions for catalytic regeneration of saturated carbons.