Granular activated carbons from powdered samples using clays as binders for the adsorption of organic vapours

Granular forms of powdered activated carbons were obtained using clays (a natural montmorillonite and a synthetic laponite) as binders. Two carbons were essayed: a commercial sample and a carbon obtained by chemical activation of cork with K2CO3. The effect of the amount of binder on the adsorption capacity of the samples was monitorized by adsorption of nitrogen at low temperature. On the laponite based extrudates the influence of the calcination temperature (300-600 C) and atmosphere (air and nitrogen) was studied. Besides the textural properties, the impact strength and a first approach of water stability of the extrudates were evaluated. The results show that calcinations under nitrogen do not cause changes in the textural characteristics of the samples, but when air is used, temperatures above 400 C must be avoided. The water stability is observed only for extrudates that were calcined at least at 400 C. The hydrophobic character and the potentialities of the extrudates prepared with activated cork and laponite (calcined at 400 C under NZ) as VOCs adsorbents was demonstrated by the adsorption studies of water, methylethylketone, 1,1,1-trichloroethane, cyclohexane, ethanol and trichloroethylene. (c) 2006 Elsevier Inc. All rights reserved.