Study of Hydrogen Sulfide Adsorption on Activated Carbons Using Inverse Gas Chromatography at Infinite Dilution

Abstract

Adsorption of hydrogen sulfide on fifteen samples of activated carbons (unmodified and catalytic with introduced basic nitrogen groups) was studied using inverse gas chromatography (IGC) at infinite dilution. Porous structure of carbons was evaluated using sorption of nitrogen. From the retention volume measured in IGC experiments, heats of adsorption, free energy of adsorption, entropy, and Henry's constants were calculated. The results showed the dependence of these quantities on pore sizes of the adsorbents. The strong dependence of the isosteric heat of adsorption on the temperature of measurement and, following this, unusually high heat capacity suggest the strong effect of specific interactions and catalytic influence of carbon surface even unmodified. The calculated Henry's constants are in agreement with the literature data. The adsorption on carbons with incorporated basic nitrogen groups is characterized by stronger adsorbent−adsorbate interactions than on unmodified carbons.