Sorption of water vapor by active charcoals

Abstract

1. A detailed study has been made of the sorption isotherms for water vapor on nonporous,thermallytreated carbon black having a known specific surface, and also on a number of samples of active charcoal. 2. It has been shown that, for carbon black and active charcoals, the main rise in the sorption isotherm up to its point of inflexion corresponds to monomolecular adsorption. In the direct sorption process, the region of polymolecular adsorption extends up to high relative pressures, approaching 0.95. For the investigated samples of active charcoal, the process of capillary condensation does not play an important part. 3. An exposition is given of the concepts developed in our laboratory concerning the mechanism of the sorption of water vapor by carbon adsorbents: it involves the hypothesis of the determining role of hydrogen bonds in the adsorption of water vapor. It is shown that the experimental results are in accord with these concepts.