(395v) NET Adsorption Thermodynamic Framework for Microporous Adsorbents

Adsorption thermodynamics is based on Gibbs dividing surface.  Fixing the “location” of dividing surface has been a challenge both experimentally and theoretically, especially for microporous adsorbents which are used in all industrial processes.  Often helium has been used in the past as a probe gas with the assumption that it does not adsorb.  There is ample evidence in literature that helium, like all other fluids, do adsorb.  Therefore, the entire thermodynamic treatment of adsorption has been based on this questionable assumption.

Recently, we introduced a novel approach to define the Gibbs dividing surface called “Net Adsorption.”  Net adsorption completely eliminates the need for a probe fluid to locate the dividing surface, thus circumvents all questionable assumptions.  In addition, using net adsorption framework greatly simplifies experimental and simulation efforts.

This poster will explain net adsorption, provide the thermodynamic basis, and show benefits of net adsorption over “excess” and “absolute” adsorption including some examples.