Water adsorption on carbon molecular sieve membranes: Experimental data and isotherm model

Water vapor adsorption on carbon molecular sieve membranes is studied. Structural characterizations and pore size distribution determinations were performed on three different samples. Water adsorption isotherms displayed type V behavior and evidence of desorption hysteresis. An isotherm equation for water adsorption in microporous carbons was derived from the basic formulation of the Do model, originally developed for activated carbons. A mechanism for water desorption was also proposed. For each adsorption and desorption isotherm equation there are four parameters, three of which are identical for adsorption and desorption. Good description of water adsorption experimental data was obtained.