The applicability of the numerical algorithm for the evaluation of isosteric heat of adsorption Original Research Article

The calculation of isosteric enthalpy from an adsorption equation, and the comparison of theoretical enthalpy plot with the values measured calorimetrically is the fundamental condition for the verification of the correctness of an adsorption model. However, sometimes it is very difficult to get a simple analytical form of adsorption heat equation i.e. the isosteric heat of adsorption cannot be easily calculated from the thermodynamic van’t Hoff relation. For such cases we propose the new numerical algorithm. The applicability of the algorithm is checked out for two cases of the D’Arcy and Watt water adsorption isotherm equations. It is shown that the algorithm can be successfully applied for the thermodynamic verification of arbitrarily chosen adsorption isotherm equation, even possessing complicated form that disables simple analytical derivation of the heat formula.