STUDY ON THE CALCULATION AND APPLICATION OF THE UNIT ISOSTERIC ADSORPTION ENTHALPY

Abstract

A series of isothermal adsorption experimental data of lean coal and fat coal has been converted into a temperature-pressure-adsorption equation. The slop of the lnP vs 1/T straight line of Clausius-Clapeyron equation proves that physical adsorption is an exothermic process. The Unit Isosteric Adsorption Enthalpy (UIAE, KJ•mol-1•cm-3•g) is defined as a unit adsorbed amount enthalpy at a fixed adsorbed amount andthe calculation method is presented. The UIAE calculation results prove the surface of the adsorption medium is not uniform, and the interaction between the adsorption molecules occurs. At the same isosteric adsorption condition, lean coal has higher priority to carry out the exothermic process than the fat coal.