ADSORPTION EQUILIBRIA OF PURE VAPORS AND THEIR BINARY-MIXTURES ON ACTIVATED CARBON .1. SINGLE-COMPONENT EQUILIBRIA

Absorption and desorption equilibria of three organic vapors on two kinds of activated carbon are investigated theoretically and experimentally. The application of the adsorption integral equation to microporous adsorbents is discussed. It is shown that the Dubinin theory of volume filling of micropores (TVFM) provides an improved method for describing the adsorption of organic vapors in the micropores of the carbon. From adsorption and desorption experiments, the transition from micropore filling to capillary condensation in mesopores can be observed. The corresponding adsorption potentials are related to a pore radius of about 1.6 nm. A modified Dubinin-Astakhov equation is proposed, which takes into account the end of micropore filling and the characteristic curves by means of a limiting potential AGr. This equation describes the isothermal field of all six investigated systems very well in a wide temperature range (20 - 150 °C) with temperature-invariant parameters. © 1990.